Modo only has 18 games left on their season, and obviously playoffs won't be happening for them. The Marlies have 38 games left, and are just 2 points out of a playoff spot. They could desperately use a guy like Nylander too as their centre depth has been awful all season long, especially with Smith/McKegg/Carrick being used on the Leafs. They've had to rely on an ECHL player to fill their 2C spot for most of the season.
They also have Swedes like Loov and Granberg (Nylander and Loov were teammates on Modo last season) so they could help ease the transition for Nylander, although it's not like he's unfamiliar with North America growing up here.