I seriously suspect that lockboxes, lobi store, dilithium mining, the Utopia Planatia map, the friday-the-thirteenth mission, Atrox carrier, Armitage Heavy Escort Carrier, Feresans all came out from that 20% time that the STO team had.
However, the basic problem still remains - the team's hands are still tied even after Season 6 is launched as they will have to worry about Season 7 which is scheduled for end of the year. Very likely, this 80-20 split will continue for the rest of the year.
All this means that when Season 6 is released in July, we will see a huge injection of game content that the team has spent 80% of their time working on. But after that, we will go back to getting a tiny trickle of content from August till Season 7. Worse still, replacing Heretic and Gozer won't cause a new "creative spurt" because the new devs will be working under the same constraints that Heretic and Gozer had.