I have written to the feedback link.
And they also state in their terms:
- If you provide any ideas, suggestions, or recommendations on this site regarding Apple’s products, technologies or services (“Feedback”), Apple may use such Feedback and incorporate it in Apple products, technologies, and services without paying royalties and without any other obligations or restrictions.
I am not expecting this to be seen by apple but it would be seen by people.
I would like to think that this is more of a place to get the idea out so that other people who feel the same could write to the feedback link as well with good reason for this feature now that we have gamed out the issues (more people more attention from Apple if they send it to the feedback link) But again not my intention to think this is the place to put the feedback for Apple to see. I am just writing to the forum. Someone would have already gotten their answer before coming across my reply post anyways.
Also I was editing the long thing and I guess you can't edit after someone replies so here is the edited Long Thing that is writen out a little better below.
I do see speculation is prohibited but in their terms, it also says this:
Post constructive comments and questions. Unless otherwise noted, your Submission should either be a technical support question or a technical support answer. Constructive feedback about product features is welcome as well.
So it is also stating that I can post constructive feedback about product features. I think the feedback I was providing was not trying to bash anything but to talk about why it is useful and why it would be really nice to have the ability to sync messages. We were also talking about the "idea" and whether there were any issues that could come from such a feature. Which you made some points about storage being an issue, privacy being an issue, or just that the system is not set up for it. But I would have to say that many applications/services already do this and sync their messages like Google Hangouts, WhatsApp, Facebook Messanger and if they are not having issues with storage then I would think (sorry if this is considered speculation) that Apple could also deal with that storage demand. I have already made my points about privacy referring to the concept of email being stored on servers so why are iMessages treated differently? They are very similar in concept, being that they are both text and sent for the purpose of communication. We know that the system is set up to push from the device and passes through an apple server and if something is "near" (whether that means the device is on and connected to the internet or both devices are on the same network) then that message will show on the other device. Again this conversation I would say is considered constructive feedback and touching on the sub-topics of why iMessage syncing would be a great feature.
To your point of someone being grateful that they deleted a message on one device on accident and were happy that it was on another is kind of a major edge case. It is not like your other devices get all your messages every time there are times when the other devices don't. I have had times when I would send a message from my iPhone and being in a bad service area so it had to be sent as a text message but when I go to my Mac later and want to reply to that conversation it is not there. You could solve this by making it so a device in a bad service area that has to send a message as a text will wait for data service to come back then be able to send those messages through the Apple servers to be on iMessage and to get to the other devices. My point being the few times that people are happy that it does not sync and can get deleted messages back from their other devices does not outweigh the number of people who are annoyed that the messages they deleted do not delete from there other devices or that they can't continue their conversation they started on the phone.
I do see that there would be more processing and storage that Apple could potentially have to deal with but being that so many other companies some of which also provide a whole suite of services and still allow for syncing messages. It just seems it would make sense for Apple to do so with their messaging service.
And also I would like to say we probably would not really have to store the messages on the server forever it's just syncing the instructions to make those changes on all the devices. So here is a concept of how that could work - if you have one device and you are signed in with your Apple ID you could have a new iCloud setting toggle for iMessage and turn that on for the device. Then that device would be a part of iCloud iMessage and if you want another device to sync the instructions for deletion of messages or get the queue of messages to be synced from the 1st device you have to sign that other device in with your iCloud account and turn that option on from iCloud settings like you do with most of the other iCloud features.
My point is that it is conceivable to have this as a feature without having too much of a storage issue because its not storing the messages it could just store the instructions of what needs to happen, the privacy is similar to storing email, and the cases for people liking that it is not syncing and can get to a message on another device if they accidentally deleted a message are small edge cases and would not outweigh the ability to keep your messages the same on all devices. One more point is what if I wanted to get rid of a message that I did not want at all, I would have to go to my Mac, iPad, iPhone 6s, and iPhone 5s (for Development / testing) to make sure it has been deleted...
I hope that this constructive feedback has been explained enough to show the reasons we should definitely have iMessages synced across all devices.