Aren't we going towards a dungeon deadlock ?

[Reynhart]

In 3.2, soldiery will dissappear, poetics will become exchangeable for law, esoteric will become uncapped and a new weekly cap currency will be added.

Again, until now, we didn't have the "level cap" issue.
Some people might now have the expansion, or just want to do their relic quest at level 50. Thus, they still need one type of tomestones available.

In the old days, DD and AV used to award a small amount of philosophy tomes, so you could have a few by the time you got to 50, at least enough to buy a ring or something. I kinda wondered why they stopped doing that

Yes, a few. Too few to buy anything relevant without really painful farming, which roulette was supposed to reduce.