[MayeulC]

As far as I know, the center core was a block five one, but they didn't intend to refly it anyway, from what Elon said in the press conference. Maybe they intended to study it? If that's the case, there will probably be another "expandable" block five flight.

[collinmanderson]

According to reddit, even the center core (B1033) was Block 3. No block 5 cores have flown yet.

https://www.reddit.com/r/spacex/wiki/cores#wiki_.5Bfh.5D_b10...