Not gossip. Not even an opinion, as I don't know what was said and nor does anyone else on this thread.
It is speculation. Based on what has been said by the people involved.
Harry has said in print that he had a conversation with Charles, and Charles was 'disrespectful' about Meghan. As he didn't confide the details of the conversation it could have been an expletive-riddled rant about her, or saying that she wasn't welcome due to the hurt the family felt over the OW interview.
The first would be disrespectful, the second would be a simple statement of fact that Harry didn't want to hear. I can imagine a range of other options, but that's irrelevant. The point being, Harry saying that Charles was disrespectful to Meghan in that conversation doesn't make it necessarily true. Or untrue.
But Harry seems to see it as a competition between Meghan and Kate, if he was happy with Meghan not going as long as Kate wasn't going.