I don’t know anything about boxing but my friend at the makeki, an ex-boxer, reckons that a Joshua-Parker fight is a long way off.
For a start, there is no financial gain for Joshua by fighting Parker; the promotional dollars are not there.
I read, that after the fight, people attending the fight were asked whether they had heard of Parker. None of them have heard of our boy.
While this is not significant by itself, the fact that Parker is not a well known in the UK would suggest that a Joshua-Parker might be difficult to promote London or anywhere in the UK. I don’t know whether such a fight in the USA might be possible, or promotable.