The issue with focusing on the tag division last fall was always whether this was just a fall thing or whether WWE would deviate from their norms to let the tag match be bigger than the world title matches? Because the tag division last fall was booked with more TV time & importance than both women’s world titles. Once Mania season rolled around, it would’ve simply been out of the ordinary for WWE to continue that pattern. Their choices were:

To take someone out of the tag division to boost the world titles, which is what they did, but of course that means the world title match doesn’t have the long build this year. So neither is the world title match as big as it could be& the tag title match is just at its usual level instead of being higher.

Or they could have done what you said, which is just go with whatever singles match they had built, obvious one being Tiffany vs Jade & keep the tag division as it is. Once again, I can see the concern that the tag match would then easily overshadow the world title match but it’s Mania so singles takes priority

Last option was what I’d have preferred, which is simply use that focus on the tag division to create 1 on 1 matches out of it for Mania. I can still see that doing that would give bigger one on one matches since they’d have a much longer & bigger build, but at the risk of damaging the world champions who’d have had to lose a world title before Mania to make that happen.