Is anyone surprised by the lack of TokuDB support? Percona is primarily an Oracle MySQL fork . The InnoDB changes in MySQL 8 represent something entirely different. Good, but different.

I don't think I am being too speculative when I say, I am sure Oracle are in no hurry to make MySQL a serious contender to Oracle just yet! But MariaDB could.

Me and many others had hope that TokuDB would be the death of InnoDB in MariaDB, and the catalyst to a truly amazing open source database.

RocksDB can still come into play later, but it's not going to help users migrate from other RDBM systems, fix existing "missing" features from MariaDB, nor is it anything I don't think, existing TokuDB users care about. 

Richard