Technically they brought her back as an alternate-universe version who then travelled to the past; and that her helping restore the timeline would've been a much better death/send-off even if it wasn't quite the same Tasha.
Then again she was given another (offscreen) bad death even then pretty much, being killed trying to escape after spending years in Romulan captivity.
I think in a few ways they were mainly trying to top Best of Both Worlds's cliffhanger with Redemption Part I which ended season 4. "Tasha's back but she's a Romulan? What the?"