Need to look at that in the context of Luke 8:19-21. Pretty clearly not a rebuke of honoring His Mother, Mary the Mediatrix of all Grace.
Agreed, not a rebuke of honoring His Mother, Mary. Rather, it is an establishment of priority! Jesus comes first! On a scale of 1 - 10, He is 10! Mary is a 7 or 8! Similar to St. Peter,etc. or as us Protestants would call ‘em: Apostles John, Peter, Paul, etc.
Mary is an EXAMPLE of Grace, but not the Mediatrix of all Grace.
Only Jesus Christ is the giver of all Grace, Mercy and .... Salvation! And we can have a direct relationship with Him! I do!