This is true that Barcelona have had several wins over Man United , but I do think that this time around it's going to be a different ball game, looking at Man United form and Changes over the years in both clubs. Barcelona had this incredible coach Guardiola and players, Lionel, Xavi, Iniesta and more compared to what they have now, basically a lot of things has changed which could affect the result too.
Without Xavi, Iniesta and other Barcelona's veteran players, they're able to beat Manchester United. Check the match on April 11, 2019 and April 17, 2019, only both Messi and Suarez playing as the strikers, the midfielders are same like the current year. It's really wrong to say Barcelona is really different with the old one, Messi is a GOAT, but football is a team play and the current Barcelona's players are good enough.
In the recent meetings of Barcelona and Manchester united, Barcelona always take the convincing lead. But this time around I am not sure Barcelona will be able to maintain their record because Erik ten Hag is coming with high pressure to destabilise Barcelona.
Any team can win because they are both doing wellin their local leagues but in Europe I would trust Ten ahead of Xavi.