It depends. As a rule I don't think that it's possible to have a healthy relationship with an age gap larger than ten years if the younger person is still under 30.
If you add the layer of the older party being in a position of responsibility it's definitely not ok.
It comes back to power imbalances.
People saying they met someone and they are still together years later, aren't necessarily a good example either. It doesn't mean that relationship is healthy even if they are still together.
I think the issue is with the younger party almost idolising the older one and that giving the older one a level of control over the younger one.
It's incredibly difficult to counter that. And I don't think you see it whilst you are in that relationship either if you are the younger party because you lack the life experience to understand why it matters.
A man older than 50 trying to start a relationship with someone in their 20s knows these dynamics. Someone working for the BBC definitely does. Especially someone in the role this guy has. They are aware of previous cases of abuses of power because they are educated in these matters.
There is no reason why this man should have been contacting anyone this age apart from if they are colleagues or friends of their children. They don't have the same social circles. It's just stupid and putting himself at risk of accusations even if nothing untoward has happened. We have evidence he HAS had contact with someone who he'd be extremely ill advised to contact. This can't be dodged in any explanation.
Approaches initiated by someone younger should be seen through the lens of fandom and treated through that lens. To protect both the young person and the celebrity.
That's why I lack sympathy for BBC guy. Especially after speaking to friends who work at the Beeb.
Ultimately he has to take responsibility for the ill advised contact (like Schofield) even if found innocent of everything else. And he can not continue in his job simply for that reason. Because safeguarding employment policies to protect young people and the reputation of the organisation need to exist - precisely because of previous scandals (of the most extreme severity) . Anyone who works for the BBC KNOWS the history on this. There are simply no excuses. It's just being a dickhead.