I don't think anyone is saying people shouldn't have whatever makes them comfortable.
But this isn't about 'each to their own'. It's about messages in advertising, about influence. Most of us think we're immune to advertising because we can consciously dismiss it, but our subconscious minds absolutely are influenced, especially when we're young.
Not so long ago there was a scandal around the fashion industry featuring size zero models, literally making money while 'modelling' anorexia to young women, some of whom went down a path they would never have otherwise been led down.
Here we have a business whose purpose is to make money via sales in the short term and via bolstering their brand in the long term – for example by flashing their inclusivity credentials at the younger generation, who after all, are going to be their most lucrative market because they will be buying period products for many years to come.
These are the people they're targeting. And if one single girl sees this and thinks, "How great, how inclusive, how kind, and I'm a bit uncomfortable in my body, or a bit gender non conforming, or think I'm gay," and if this smiling trans model helps to push her down a path of mutilation and medicalisation with who knows what long term effects on her health, even if it's just one single girl, then fuck that.