MCU: 16 Things We Learned From 4Chan's Latest Marvel Movies "Leak"

The Rumour

Though some actor's contracts are already fulfilled, the plan is for ALL notable characters already introduced into the MCU to make special appearances, including Pepper Potts and Jane Foster. They don't HAVE to come back, but apparently the arrangement is for them to play cameo roles, thus avoiding the need to renegotiate new contracts.

Response

The cameo explanation works, but at the minute there's no need for either Pepper Potts or Jane Foster to actually come back in Infinity War. Tony Stark seemingly confirmed that he and Pepper are no more in Civil War and rumour has it that Thor will be getting a new romantic interest in Ragnarok, so Jane too has served her purpose.

None of that is particularly nice, of course, as both characters have been abused in the name of the MCU and never given anything like enough material to work with (which is why you'd forgive both of them for not wanting to come back), but it's the corner that the Russos have been written into.

If they're genuinely coming in for cameos, it would probably be quite surprising.