Good guess, yes. :-) From a brief look it seems that these days (I don't think it was around when I first looked a few years ago) MusicBee instead of iTunes on desktop and GoneMAD Music Player might work as a similar combo with bi-directional play count and ratings sync (although I've found somebody saying that this didn't actually work on a latest Android version [1], so hmm...), but it seems the podcasts handling might not work as it currently does.
The problem is that while I don't need the podcasts syncing for regular podcasts (for which a separate podcasts app on my phone would be perfectly fine, and besides I don't listen all that much to podcasts that way anyway), I'm also managing my collection of radio comedies I've scrounged together from all sorts of places as podcasts in iTunes (by simply manually setting the media type to "Podcast" – luckily on Windows, where iTunes hasn't been split up into its components this is still possible), so that
a) they're all together in one place and not cluttering up the music part of my library
b) especially to get the nice at-a-glance listened/not listened/partially listened display, and
c) while iTunes allows setting the "Remember my playback position" for any kind of file, Rocket Player apparently supports remembering the playback position only for podcasts
I've got no idea how GoneMAD and MusicBee's file syncing behave in that regard, but a quick test installation of MusicBee showed that while I could get used to it as an iTunes-replacement for my general music library, it doesn't allow manually importing files as podcasts, meaning I'd have to resort either manually hacking the database, or setting up some sort of fake Podcast running on a local HTTP server in order to import new episodes... :-/
At least for now the old versions will keep working, and if some future Android version does break things, I guess I'll decide what to do about it in terms of a replacement at that time and not now…
Though I guess it does mean that my personal main bug in iSyncr [2] won't ever get fixed now, so maybe I need to resort to APK hacking after all…
[1] Which is how I found out about iSyncr + Rocket Player having been sold in the first place.
[2] After a file has been synced, it won't be synced again if any subsequent changes that don't change either of title/artist/album (or possibly file size, but due to metadata padding small metadata changes won't necessarily change the total file size) happen within 24 hours [3] of the original sync.
[3] I think this is trying to work around the fact that Android reports the file timestamps in local time, so due to either travel or even just summer/winter time a file might suddenly appear as outdated as compared to the last modified timestamp on the desktop. As my desktop with my music library, is in a fixed location, for me 24 hours is excessive, though, and 1 hour to cater for summer/winter time would be enough.