Only to United in prem? Surely thats not true unless he's a United fanboy.
It makes sense really. Liverpool have Mane and Salah, he wont go somewhere he wont play regularly. City have Mahrez as backup to Sterling and Sane, plus he left them. Arsenal cant afford. Spurs cant afford. Chelsea have a transfer ban, plus are on their way to a decline without Hazard, plus haven't been spending anywhere close to as much, plus spent 60m on Pulisic.
United on the other hand is a massive club, he'd have confidence to come in and be the main guy, get the #7, play at OT, at a club that will eventually sort their shit out with all the money they spend to get back up their (plus see himself as the catalyst to do that), get paid loads, etc etc. Not to mention needing a right winger for ages, him already having good friends at the club, and him wanting to go back to the premier league gives us an advantage over the other european clubs for a change. Just think the cards line up nicely for us here, but problem being Dortmund have no reason to sell this summer so it'll likely be next summer.