The problem with any Marner trade is going to be his current cap hit and is salary expectations on an extension. Contending teams don't have that kind of cap space to spend on a winger with a less than stellar playoff history. Rebuilding teams with a top 10 pick are probably better served just using the pick as whomever they get in the top 10 this year will be a decent player that better fits their window.
Leafs are either going to have to take a similar contract back or if they are looking for futures it won't be a top 10 pick. It will be later pick and prospect type deals. The biggest challenge is Marners salary ask, no one will give up a lot without an extension in place and unless Marner is willing to take under 10M, don't expect to be blown away by the offers. Throw in limited teams he may waive for and leafs will not get fair value.
Of the teams with top 10 picks
SJ/Hawks/ducks/BJ/Calgary all probably in the asset accumulation phase of rebuild - not going to trade the pick.
Mtl may be trying to exit and Gorton has a history of acquiring players to accelerate a rebuild (panarin with NYR) but they will not blow a premium asset on Marner at >10M). likely to make their move next yr via free agency or if its trade it ssomeone younger not that close to UFA.
Seattle might but are probably better served on UFA market. They need more young guys than wright and berniers
Ottawa is capped out - unless Leafs want an injury prone Norris as part of the return?
Jersey might have interest but someone like Timo meier has to go back to make cap work
Utah is probably the best bet, they have a ton of picks and may want to make a splash- maybe Marner is that splash.
Something like Jets did with PLD is possible with more of a contending team but will be difficult unless Marner is willing to extend around 10M. Even then not sure he is worth 10M. Teams with young guys needing new contracts do now want to bring in an overpaid Marner that resets their internal salary structure like tavares did for Leafs.
He is tradable but don't expect to be wowed by the return, the best return may be freeing up cap space. On a player for palyer deal Leafs really need a right D back. Jones fits that bill.