Slightly old news, announced on Twitch on May 18, but Avrae and its creator are joining the D&D Beyond team, so we can probably expect its usability to improve greatly soon.

From the acquisition FAQ on the Avrae Development Discord Server:

Will Avrae still be free to use?

Yes. InitTracker, SRD Lookup, aliasing, homebrew functionality, etc. will all still be free to use. The only thing that will cost money is lookup for non-SRD races, items, features, etc. through D&D Beyond.

Will I have to buy all the content I've bought on DDB again to use it on Avrae?

Nope. If you've purchased content on DDB, once the DDB-Avrae integration is complete, you will be able to use the lookup commands (and any other SRD-locked commands) with content you're licensed to use.

What does this mean for Dicecloud/GSheet support?

Dicecloud support has been explicitly stated to be uneffected by the merge. GSheet support is expected to remain as well.

What about DDBSheet support?

DDBSheet support will be vastly improved over the coming months. Now that Zhu is entitled to the use of the DDB API for use in Avrae, he no longer has to manually figure out how DDBSheets work, resulting in much fewer bugs.

What will happen to the Avrae Development Discord server?

This information is likely to come to light in the coming weeks. Stay tuned to #announcements for updates!

What happened to Zhu's Patreon? Will I still be able to donate to server upkeep costs?

Zhu has personally elected to take down his Patreon, thinking it obsolete. With the acquisition of Avrae by DDB, Avrae's upkeep costs are now paid for by DDB. I am VERY grateful to each and every single Supporter - thank you all so very much for helping to keep Avrae online these past few years. <3

Will Avrae still be open source?

Yes. Avrae will still be open source. You can view the source code and contribute on the Avrae github.