It might be bad news. Because either we can manually upload both 32bits and 64bits APKs at the same time, or we'll have to switch to Google app signing keys for App Bundles. Last time I checked this new signing key system, it looked pretty nightmarish (I saw a thread about it on the Adobe forums, which I can't find again unfortunately. It seemed extremely complex, that's why I always opted out).
Edit: Tuara seemed to just answer this. Thank you! 🙂 As long as I can upload both APKs, I'll be fine, I guess.