According to Klaus Zaugg (Watson), Eichmann is still looking for a fourth import player to add to his roster. He is apparently "negotiating intensively" with the Swede.
Jesper Boqvist has a valid contract with the New Jersey Devils until the end of the 2021-22 season. He is currently in New Jersey at the Devils' training camp. The NHL team just had their first on-ice practice session on January 1
Whether or not he would be able to join the SCL Tigers would thus depend on whether or not he makes the Devils' opening night roster and, of course, whether or not the Devils are willing to loan the forward to the National League team.