I hadn't seen much on $SAVE previously, but I'll give my reaction...
Backdrop is a tough market environment (I see the bear market continuing, I don't see a bottom/capitulation yet thus have sold quite a bit myself). This seems to be widening merger arg spreads. Look at the interest Twitter acquisition. Some of the risk is unique to Musk's craziness but the general idea of ~renegotiations seems broadly applicable in a bear market. So I'm more hesitant about deals not closing than I normally would be.
And I also expect spreads to stay wider than usual until close and I don't necessarily want that medium term multi-month exposure. That's why the VMWare deal tempts me, because I think VMWare holders are motivated and I think it could have a relatively low risk short term bounce. (But I'm not certain).
Then with SAVE in particular it sounds like you have the unknown of anti-trust risk. I don't know why Spirit thinks the Jet Blue offer has much higher antitrust risk. JBLU is $3.3B vs Frontier $2B (and Spirit $2B), so I don't see a gigantic discrepancy there albeit Jet Blue is bigger. But maybe there is more geographical overlap with Jet Blue and thus more potential monopoly power?? Or maybe it's by another measure? Either way anti trust is hard for me to handicap. Plus there is the hostile tender by Jet Blue and I am not sure how to handicap that either.
To your point, sure there is the potential that the deal gets recut higher. Maybe Frontier gets pressured and is willing to up their bid to make the tender less appealing. But for all I know the whole thing is a crapshoot so I don't see where I have an edge to price it better than the market.
(I'll assume by your lack of comment that you have no view on $VMW.)
Stepner