Yea, I don't expect that there'll be more than 50 trophies. That's usually the standard. It will probably only give you trophies for doing a large segment f things rather than just a trophy for every little thing you do. If that's the case, It should be all silver and gold imo
A proper Skinner box will have a handful of trophies early and often.
Say, a trophy for equipping your first cross class ability, for starting your first job in Magic/War/Hand/Land, unlocking Grand Company content (previously level 23, who knows what it'll be now), and then petering out until you get your first level 50, until you beat all the primals, etc.
In-game achievements will be for little things. Even FFXI had the titles for completing content or defeating certain mobs (and then amusingly those titles were required for later requests or for rewards in Abyssea. Just got my Atma of Future Fabulous for finishing WotG and getting that title.)