If Enid is joining RA in the future then it probably means she´ll work alongside her as a future trooper. If anything, since she´s the reason RA discovered the weakness of their enemies, she´ll have to work harder than ever. So she´s in the same position as her.
Even with all of that aside, it´s still fucked up that she just chose to abandon her best friends who she has developed a bond for 3 seasons over some pussy. Time travel fix or no fix, you can´t deny that.