I think that the population in Texas is higher than USW, the hence the upgrade should be done there first.
But, since we don’t have access to the info that the dev has, perhaps even tho there are less player, just from being created before it has more load from buildings and stuff, plus more people proper geared to deepen in UW.
It’s up to him, but you’re right that servers with population on high should be priority
Regards