If I were a mathematician I would try to somehow relate these two effect. Wesley, please have patience with a layman. In short, no. In short, no. Your intuition about pressure does not apply here, and relativistic time dilation is not a significant effect in galaxy formation.
Gravity exists due to mass, even if no pressure exists.
It is not true that gravity can be understood as time-dilation. Mass, via gravity curves space-time. As such, the geodesics on which light travels become curved. All rights reserved. Used under License.