I wasn't paying much during the finale, except for when Fred was brought to the woods, beaten up by all the former handmaids (and June) and later confirmed to be dead. I guess Serena is June's next target. Because you know once Serena finds out, she'll likely retaliate or rejoice.

most perfect end for Fred ever. The only thing that could have made it better would have been seeing Serena's reaction to Fred's severed finger

wow it was just so satisfying to watch all the girls murder Fred. absolutely amazing. we don't get enough of these moments on tv where the dirtbag gets what he deserves.
it's very sad though that I guess June and Luke will be separated now since Luke didn't agree with that decision

now what about Serena? is she gonna be sent back to Gilead too to become a handmaid?
it was so funny how she waited for Fred on zoom

it's already hard to wait for the next season and it just ended

Short answer? No. But that doesn’t mean that we’ve seen the last of Serena “working” — Yvonne Strahovski’s word — the American agent played by Sam Jaeger. “They’ve both been using whatever relationship they have to their own advantages,” the actress explains. And once Mrs. Waterford realizes the full extent of everything that went down in the Season 4 finale, “I don’t think she’s above reverting to” flirting with Tuello… “She plants these seeds. She sets these things up so that she can use them, if she needs to, if it’s convenient for her down the line. And Mark Tuello is totally one of those people.”
https://tvline.com/2021/06/17/handma...rena-joy-mark/