I thought they had posted that they'd already made the decision of what platform to switch to, but weren't announcing it yet (which seemed weird to me). Sublinks honestly would make some sense given the Lemmy-compatibility and emphasis on mod tools, which I know was a constant pain point for them... but IDK if it's mature enough. But yeah if you told me they were waiting for it to mature so they could switch over, that would make sense.
I'm also very curious to see how (if at all) you migrate an existing server with all its existing ActivityPub keys and subscriptions to a new piece of software, on the same domain, without unfixably breaking its federation with every other instance. My guess is that they will switch to a different beehaw.(whatever) domain but I'm curious if there's a good solution I'm not aware of.