I think it would help if you gave specifics here - “good things” is not a lot for the devs to go on.
Also, check out this Twitch segment of the March 14th 2025 Developer Livestream.
Whilst not specific to Mexico, Jorg mentions that for WUs he needs to get a Vexcel plane with the right camera equipment & crew to these locales for a year or two - and to be patient. It is unlikely that MSFS will have any Vexcel updates to these additional areas in South America until 2027 or 2028.
My takeaway from this is that:
There appear to be a limited number of aircraft with this technology, and more requests for its use than available aircraft, so this can delay the creation of WUs unless the locales that the aircraft are photographing can be used MSFS and Jorg can negotiate the rights to purchase the data.
So IMO, unless the MSFS team makes a specific announcement about Mexico, a similar timeline (or later) for Central American countries may be a reasonable assumption to make at this point.