I’m not against the idea of a Jennifer Lawrence cameo, but maybe it’s better to leave Mystique wherever she is.
The shapeshifting mutant was at her peak in X-Men: Days of Future Past, but took some major steps back in X-Men: Apocalypse.
Lawrence’s lack of enthusiasm to “blue up” and play the character was pretty apparent in that film and seeing her in Guardians probably isn’t too high on many people’s lists.
Fox has attempted to make Mystique a pillar of the X-Men franchise in accordance with Lawrence’s own rise to power and that has worked to mixed results.