I wonder if the last minute crisis was a change to the bonuses that humans and half-elves get along with their floating +2/+1?
Sven made a comment about how they are a company that does last minute changes, and that's one I could see them responding to because of the feedback. Shrug. Just a thought.
If anything is probably the other way around. They probably had demographics and player data, and playtesting telling them to go with Tasha's as well as wotc themselves and the lore
Say hypothetically they see 95% of people are playing human with 4% playing teifling, gith, and elf, and 1% playing short races. Keeping human in their former gimped state just isn't a smart Idea, they need to be able to get that +2 so new players don't feel discouraged that a gnome is a more meta character for their wizard.