I doubt that honestly.
Raphinha is in his best form these days. Why would Hansi Flick decide to cut him from the starting lineup to "rest"?
It doesn't make sense while he is one of top goal contributors. Rashford will need to earn his place there. He will need to work hard to stay fit and impress the manager. I can't say he has been in his best physical shape recently.
Barcelona only take benefit from his loan status, and ditching Raphinha would be the club's biggest mistake. I have my doubts about Rashford, he is the type of player who is lazy to work hard, always waiting for a pass, not suitable for Barcelona's style of play which is all active in carrying out roles. For that Rashford will have a hard time if he stays with his poor playing style.