On your first point, we don't know what conversation was had around the shirt. To accept your argument we'd have to assume an unrealistically limited conversation took place between the player and the club both before and after he refused the wear it. The idea that the club didn't brief the players on the decision to put the colours on the shirt and that they as professional footballers living in 2022 had no grasp of the context behind the gesture being made is far-fetched. The idea that this conversation wasn't had with Gueye even after he refused to wear the shirt stretches credulity to its limit.
My second point was a general response to the idea that it's some huge free speech issue for an employee to be expected to embody the professed values of their employer whilst representing that employer. If I was sent to a conference on behalf of my organisation and refused to attend a mandatory session on LGBT rights in the workplace, or a keynote speech by a Muslim CEO about the struggles they'd faced in the industry, on the grounds that I didn't like homosexuality or Islam, my organisation would have every right to throw the book at me. Firstly because I'd have damaged their reputation as an equal-opportunity employer and possibly lost them prestige or business. And then, on a slightly different note, I'd have demonstrated an inability to aside my personal beliefs to do my job properly. In that situation, how could I reasonably be trusted to carry out my responsibilities to contribute to an inclusive and diverse working environment in which everyone is treated equally? If I was a manager, or had any HR role, how could I be trusted to make fair decisions on who to hire, fire or suggest for promotion?
Which leads me onto your point. No-one is asking anyone to change their beliefs or opinions in order to work somewhere. But they are asking that people who hold those beliefs don't let them affect their work, impact their ability to treat colleagues, customers, stakeholders etc. fairly and with respect or leas them to act in a manner which might impact upon the rights of others to go to work without fear or discrimination and harassment. If someone is unable to at least pretend that they're fine with working alongside LGBT people, their presence in a working environment is not congruent with a tolerant, inclusive workplace. Arguing that we need to tolerate intolerance and allow people to be subject to discrimination in order to be truly inclusive is lamentable sophistry.