I think an argument could be made that DC does exist in the Foxverse. In 2, Deadpool says to Cable “You’re so dark… You sure you’re not from the DC Universe?”. Later DP time travels to kill Ryan Reynolds before he makes the Green Lantern movie (and note, killing Ryan Reynolds in the past doesn’t cause future Deadpool to cease to exist, they’re two different people). Makes sense since no non-mutant superheroes from Marvel exist in the Foxverse, DC operates without a rival. Also, this is a nerdy shower thought, take it as you will.
I think an argument could be made that DC does exist in the Foxverse. In 2, Deadpool says to Cable “You’re so dark… You sure you’re not from the DC Universe?”. Later DP time travels to kill Ryan Reynolds before he makes the Green Lantern movie (and note, killing Ryan Reynolds in the past doesn’t cause future Deadpool to cease to exist, they’re two different people). Makes sense since no non-mutant superheroes from Marvel exist in the Foxverse, DC operates without a rival. Also, this is a nerdy shower thought, take it as you will.
Deadpool shouldn’t count for canon things since he can break the fourth wall.