User blog comment:ASDFGirl/The Future of Fossils and Archeology: Revival/@comment-2003:D4:BF14:2600:18E3:6277:CB70:66FB-20181122220426/@comment-5815431-20181122222449

It'd take them twice as much work to add new content to both 1.7.10 and 1.12.2 (not 1.10), so no, there's no chance of any more 1.7.10 updates.

1.7.10 was only really ever a popular version for mods because it was difficult for mods to update to 1.8, so now that most mods are past it, by the time this mod is for 1.12.2 there shouldn't be much of a reason to play 1.7.10. Not as many people still play 1.7.10 as you think. On curseforge 1.12.2 has almost the same amount of released mods as 1.7.10 ever did, and Mojang released some statistics a year or so ago showing it was already a tiny amount even then.

There's nothing wrong with anyone playing a version that's over four years old, but you can't expect anybody else to support that.