Hello Larry.
I typically take caution with the deletions of albums precisely because of their being no obvious way to recovering them (I was trying to find out some way of getting some database file, with the album information, inside the package that you could just replace, but I couldn't).
The way my albums disappeared was somewhat strange: my iPad didn't have the photo thumbnails so I decided to turn off iCloud Photo Library and restart it again. After turning it off, it took a while until the iPad deleted the library content, however, some photos and albums remained on the device (even with iCloud Photo Library off). I deleted them manually, and after I had a freshly cleaned iPad, I restarted iCloud Photo Library. The photos downloaded as expected, but to my horror (I have a couple hundred albums), all the albums started disappearing.
I don't have a good explanation for what happened, but my only theory is that, somehow, my album deletion on the iPad, even if apparently disconnected from iCloud Photo Library, triggered this information to be propagated into the cloud "master".
After this I went into a loop of weird attempts to recover my libraries, by using a backed up library file, but the albums would eventually disappear again and again as if there was some invisible limbo of to-be-deleted album information. Furthermore, the library is about 30k photos and 200GB, so it's a pain to be debugging by deleting and copying around a file that size and I definitely did not want to trigger a re-upload of the 30k photos without any assurance the albums would stay put after spending a week for all the photos to go back up to the cloud.
Eventually I only solved this by disabling iCloud Photo Library in all my devices, recovering the backed up library but only launching it without any internet connection. Then I manually changed the name of the folders the albums were in (I have all my albums arranged into 4 or 5 folders that collect "eras") and only then syncing it back to iCloud Photo Library.
I am confident that there is some bug with the folders, because I only needed to change the names of the folders, not the albums themselves, and there were a few folders inside those main folders (that I forgot to rename) and those disappeared as well, along with the albums inside them. Since these were only a few albums, I remade them manually, but, again, I suspect there's something wrong with the folder synchronisation.
Bottom line, I still don't entirely trust Photos, and because we don't have Vaults, as in Aperture (if one wants to use iCloud Photo Library), any experimenting is hard to do once you have a moderately large library. No photo disappeared, and the "Recently deleted" folder does give some confidence, but I have very little sense of security regarding the album/folder system. And I understand Apple is moving towards the continuous stream, with discoverability based on Geotags and other meta-information, but if you have old libraries where that information isn't present, you rely solely on the timeline, which is rather inconvenient (or impossible, as one can easily experience in the wretched Apple TV Photos app).