The honest truth is that you really DON'T know exactly what's going to happen. If one of your buyers offered you the opportunity to go 50/50 with him on the backside if you waive your wholesale fee upfront, that is very well something you might do. Alternatively you could actually close on the property and then immediately resell it to one of your buyers (aka "double close" in which case you ARE the actual buyer for the seller, even though it is technically a wholesale). Or any other number of different outcomes to your "originally intended" wholesale route could happen.
Since you really don't know what's going to happen exactly, there's no need to tell the seller that you're not the actual buyer but you're going to profit by selling to your end buyer. You don't know that for sure. That definitely could work and being upfront with the seller about that isn't necessarily bad------it's just a more difficult route to take and because you really don't know for sure that's what's going to happen in that way, I think it's unnecessary.
Most even motivated sellers want to sell to the guy actually buying the property ----and you are the necessary facilitator. You bring your marketing and sales skills to the table to profit. Sometimes, you are actually closing on the property yourself. Sometimes, you're not.