You might think that the end of the Infinity Saga means that Marvel's bloodlust is over and all of the heroes are now safely living in a haven of peace and tranquility. You would be wrong. Very wrong.
The likelihood now is that Marvel will seek to follow-up on Thanos' threat by proving that they haven't "gone soft" in the killing stakes by offing just as many characters in Phase 4 as they've done in the past. Perhaps even more. But who is most likely to be up for the chop?
It would probably be easy to stick Loki in this bunch, but he's now died so many times that actually killing him would be redundant. Just let him prance mischievously off into the distance and we'll all happily assume he's still out there meddling with the past or something.
That said, others definitely won't be so lucky...
Here's a strange one, but if Marvel and Sony fail to get back to the table to extend Spider-Man's MCU deal and he goes off to Sony for the third movie in Jon Watts' trilogy (assuming he even signs on himself), then something has to be done about the MCU version of Spider-Man. And now that he's already bowed out - if things stay as they are - he only solution for him never appearing again is for a dramatic, off-screen one.
Could Marvel really be as petty as to kill Spider-Man off-screen and then never mention him again? Well, consider this - when Fox kept ahold of the Fantastic Four rights, Marvel consciously ended Fantastic Four comics in a move that definitely didn't help Josh Trank's (admittedly terrible) reboot. So don't put it past them.