Yep -- that was it (I think). Unblocking it to actually sync to my watch had the unintended consequence of then triggering another issue (read: major bug) with "invitations": for some (stupid) reason, it decided to notify me for *every* unreplied invitation going back however long! So, for all those instances of repeating weekly meetings that I have not replied to, it synced them all to my watch as notifications (seemingly ignoring my iPhone preference which I was mirroring by default, which is to ignore invitations from my work calendar on my phone). Weird. So it took *forever* to eventually start showing the data (it really caused other problems in the interim; my watch was having serious problems doing anything that needed to communicate with my iPhone during that time).. but once it finally started presenting the alerts for all the previous invitations (I mean, we're talking about a hundred at least), I realized that was the problem now (flood gates = open).
So, I went back into the Apple Watch app on my iPhone (in somewhat of a panic) and edited the Calendar settings to explicitly disable alerting on invitation -- and voila! After a minute or two of waiting for it to re-sync, it seems to finally actually work!!!!!!
Thanks.