As confirmed by Marvel Future Fight itself on mobirum, Gwen Poole is coming to Marvel Future Fight in August!
Gwen Poole was originally created as a one-off character in a set of "Gwen Variant" comic covers celebrating the Earth-65 version of Gwen Stacy. Gwen Poole was created as a variant for Deadpool's Secret Secret Wars Vol 1 2, as a mash-up of Gwen Stacy and Wade Wilson, AKA Deadpool.
Due to the massive popularity of the character, she was later made into a fully fledged character and any connection to Gwen Stacy was dropped. Gwen Poole is from a world similar to Earth-1218, where the Marvel Universe is represented in many types of media from tv to comics to movies. Gwen finds herself in the Marvel Universe, and (rightfully) believing it is a fictional world, decides to become a costumed hero and uses her comic book knowledge of the world to her advantage.
Unfortunately, since Gwenpool is so similar to Deadpool, it may be Future Fight's way of saying, "Hey, we'll never be allowed to do the mutants, so here's the next best thing."