Guendouzi appeared to grab Maupay by the throat.
The FA has confirmed that the altercation was not seen by the match officials at the time but, because it was subsequently reviewed by the VAR and will face no further punishment.
Maupay sealed a 2-1 win for relegation-threatened Brighton – their first victory of 2020.
Calum Chambers (knee), Cedric Soares (head) and Sokratis Papastathopoulos (thigh) are already missing, leaving Shkodran Mustafi and Rob Holding as Mikel Arteta’s only fit centre-halves while Lucas Torreira also remains out.
Arsenal said they are hoping Xhaka, Soares and Torreira would be “aiming to return to training in the next two weeks”.
Maupay said he didn’t intend to hurt Leno but was critical of Arsenal players for “talking a lot” when they were leading through Nicolas Pepe’s opener.
“It’s up to the FA or Premier League to decide. I think it was an emotional moment. When a team loses in the last minute it’s a sore one and you expect emotions. I don’t think there was anything too serious. It’s one of those things. We move on and get ready for Leicester,” he said.
Pablo Mari and Granit Xhaka were injured in Arsenal’s 3-0 defeat at Manchester City on Wednesday night. Mari suffered a “significant” ankle injury that could rule him out for the season, while Xhaka sprained an ankle in the defeat. David Luiz remains suspended for Thursday’s game after his red card at the Etihad Stadium.