This is such nonsense
If they don't feel comfortable, their problem
In ultras sections they will most likely get cooked but otherwise most people in stadium will just mind their business
As long as they don't bring the necessary LGBT flags and banners with them, scream and yell to everyone about their sexuality and make a little parade on the stands... which is the unlikely part
And it is also not true they are not "represented". Starting from captains of the biggest clubs wearing gay flags on their arm, to gay corner flags, to gay flags near score board...