Never trust an Ancestry Tree. Sometimes they are correct and can be good hints, but everything they say needs to be verified, with facts or other better sources. There are very few verifiable facts from such early ancestors. At wikitree we tend to believe what the Richardson books (sources listed on the profile) say, because we know that his genealogical research is sound.
In this case someone, by wishful thinking, made this connection, but it's most likely untrue that Sir Richard and Joan had a son John. I don't see the will on the profile, but there were probably no children listed in it.
You might also look at the answers to this question.