FYI, buy up appears to now be active, and certainly looks in-line with prior years; I was at nearly 73k PQM, 29 PQS, 7.2k PQD. Buy-up to Platinum is listed at 2799.
(Given the changes we already know, I'm not dropping the equivalent of several first-class domestic tickets on 40 points; half of my travel is EWR to BOM, where most of the 777 has status. With the new JFK-BOM route, 2020 has now started as my first year with Delta.)
GLTA!