I suspect that lack of ammo in loot will cause some to actually spend less because they won't keep cycling... Something I, and I think a lot of other folks have started doing lately, is depositing via webshop purchases, which gets you universal ammo... which you then have to hunt with to convert in to other forms of ammo, shrapnel, etc.
A lot of that ammo and shrapnel gets TTed. I usually was using that stuff to repair armor and weapons, especially on the melee side since there's no real webshop option for melee users.
If that stuff isn't in the loot it will up the markup on the stuff you do get, but it'll keep folks from TTing the loot they got (ok they'll still TT the 103% and less stuff like muscle oil, but be a bit more reluctant to do that than TTing ammo that has no markup)... fewer things being sold to the TT will mean fewer folks cycling til next deposit time I suspect... time will tell what impact that will have on the economy. It could ultimately result in lower returns for Mindark and in a few months all of the CLD owners will be bitching even louder than they usually do, lol... of course, smart for MA to make this move mid-summer before regular end of year upswing.