Rather than sacrificing Raphinha, Barcelona would be better off releasing Ferran Torres, Ansu Fati or Pau Victor to give Nico Williams more space. Lewandowski is in his final year, and Hansi Flick seems to still rely heavily on him up front. The addition of Nico Williams would certainly add variety to Barcelona attack next season, and his signing is clearly a long term investment. I think the situation Barcelona will face is similar to what happened to Real Madrid last season, when they signed Mbappe and turned him into a center forward.
I didn't hear that Raphinha was on Barcelona release list even if Nico Williams is brought in Raphinha will remain a mainstay, but his position will be shifted to attacking midfielder. From several sources I heard 3 players were on the release list Ansu Fati, ablo Torre and Pau Victor well as you said this option would be better than letting Raphinha go who has contributed to Barcelona's achievements this season.
Previously, the issue of Raphinha transfer was widely heard in this transfer window and several elite clubs from the Premier League are interested in making a deal with Barcelona, even at a fantastic price but it seems that Barcelona is not interested in any offers at least until next season. The scenario might be different if Lewandowski retires for example Newcastle option of trade-off between Alexander Isak and Raphinha makes more sense.