Poulsen is more a supporting player. An outlet for long balls, hard working, but someone who opens up space for others rather than the guy who gets to be at the end of moves. Nagelsmann also seems to really enjoy having multiple strikers to choose from. Even at Hoffenheim (between Kramaric, the legendary Joelinton, Szalai, Wagner, Belfodil and Uth) he always had 3-4 strikers at his disposal, despite the club's rather limited means.
True to form Leipzig loaned Schick from Roma last season, despite already having a trusted partnership upfront in Werner and Poulsen.
They were heavily linked to Bremen's Rashica, who I could see doing well as a like for like replacement of Werner, however since Bremen actually managed to avoid relegation after all this seems to have cooled off significantly. Making Schick's loan permanent doesn't seem to be possible either, despite him playing quite well, taking Poulsen's spot.
I guess Red Bull's marketing budget is affected by corona as well and so it seem like they are forced to get creative.