It is no surprise that the Maple Leafs are looking to add or move some players. It has been out in the rumour mill for a long time. Toronto was talked about being in on both Nikita Zadorov and Chris Tanev, but with Zadorov going to Vancouver it ended the trade Toronto had on the table.
The Maple Leafs are mostly looking for help on the back end, and many teams know that. A common phrase in NHL circles is that when other GMs know you need help in an area they only send you anchors unless you want to pay a premium.
With the Flyers doing much better than everyone expected, and in a playoff position, it is highly unlikely they will part with a player in the line up easily.
The Maple Leafs don't have a second round pick for the next three seasons or a first round pick in 2025. With Easton Cowen, last seasons first round selection, and Fraser Minten, the 2021 second round pick, both exceeding expectations and looking like future Leafs. It makes sense to not include both in trades, especially if it is just for an end of season rental.