Finn didn't really 'go' anywhere (and we might still see him, but as a recurring, not a regular). He turned down Alicia's offer to partner up (professionally, but at least part of his reasoning was likely that there is some romantic tension between them, and he's involved again with his ex-wife).
I should probably look at a recap, too, re: election 'scandal' and Alicia/Diane/Cary why-she-didn't-go-back--why-they-didn't-want-her-back because I'm a little fuzzy on it, too, but... I remember it wasn't satisfying, that whatever reasons there were didn't feel organic so much as 'well, because'. The plot was reset THIS way because... They felt like it. So maybe I won't click on those links. I get where we are now, and it's 'fine'... But yeah. I recall that it was disappointing, the how-they-got-there.
Nobody's talking 'final season', but I think it very probably is. The Kings have spoken often of a seven year plan, and the titles have come full circle (Seasons 1 and 7 - one-word titles; 2 and 6, two words; 3 and 5, three words; 4, four words).