Per
the latest stats (
Archive, but it's janky), Lavos is fairly unpopular, but Xaku is on the popular side, especially at higher MRs - at 3% of the MR32 usage, it beat a fair number of Primes, although none of the truly popular ones, as you might expect from an AFK-friendly 'Frame that is also a pain to farm. Not sure if that's "save it for the holidays" popular numbers, but it's definitely on the anticipated side, especially since I think everything ahead of Xaku at high MR is already Primed.
Prepare for Xaku to cause troon anguish whenever the release ends up being, due to the strict male-male-female-female Prime release order.