TWRP 4.4 build on 5.1.1 ROM?

So, T-Mobile/Samsung FINALLY delivered 5.1.1 on the P607T and it looks quite awesome so far. My device was rooted and had twrp, so I had to flash with odin and now have neither twrp nor root. While I know that its only a matter of time before the community updates the tools to make it easy for us to root, I wonder if somebody could tell me if its okay to flash the existing twrp_2.8.7.0_4.4 build on this new ROM?

I vaguely recall reading somewhere that with Lollipop, Android moved to a new FS, but suspect this only applies to the system and boot partitions? That flashing recovery should be fine, and worst case, twrp will not stick? But, just in case, it would be great to know if this is true from someone with more experience ... If yes, then I can try to flash twrp and see if SuperSU still works through ODIN.

Thanks!
Karthik