TP to me always seemed like one of those XI concepts that should have stood with it. iirc, TP was a gauge that filled up in order to use weapon skills. In FFXIV, your weapon skills are readily available assuming you have the TP and the gcd isn't ticking. They're hindered by the gcd and animations, so I never really understood why they had to cost anything at all. This was even made more so in SB, when each job got it's own gauge, which typically gate a job's more divine abilities.

I don't play enough jobs to know which ones will be affected by the change, but I don't see how it could be negative unless perhaps TP restrictions is what prevents breaking the job.