They can cover it...if they want to. There are spare -200 tails (of course, it impacts payload) if needed. Aeromex doesn't really pay well contractually speaking, so they don't pony for a spare a/c. They have a willingness ($ speaking) to accept mechanical delay or cancellation vs a dedicated spare.
ABX will fix it; they always do..even with some delay. Press on with that 98% luv and no new agreement