tl;dr:

Finished and to be shipped Jolla Tablet was killed by impatient or disillusioned investor (holding back money to pay production) after jolla had major difficulties finalizing it in time and did no good job in general end-customer service.

Youyota tablet does have much less engineering overhead now and can ship with already finished sfos hardware adaption.
Finance production, source the parts, coordinate the production and ship to backers seem to be the remaining tasks for youyota.

Also chen does a really good job in keeping everyone informed.
If youyota fails (lord forbid), we will at least know exactly why.