No but there's a good chance this is a once in a lifetime opportunity. I doubt they would have waited till the summer. If he didn't go now, they'd have filled their roster with someone else.
The roster system is quite complicated in the MLS. There's 233 international slots across the league. Each team has a different amount of slots as they are tradeable but ot works out to be an average of 8 slots per club. There's also salary caps and each team is limited to 20 senior players.
Top and bottom of it, if he didn't go now I doubt they would hold a slot open for him till their mid season window. They would fill it with someone else. In my opinion it would be wrong to deny him that opportunity especially given we have used him in a rotational capacity.
If we'd brought in a striker in January like we should have then we wouldn't feel as let down by this.