Well its not like this is anything particularly new.
The report says what probably everyone suspected, which is that even if its long term viable, that US soccer isn't ready for it now.
Also I'd like to point out that this study was paid for by possibly one of the most rabid advocates of Pro/Rel in the entire US soccer system, the fact that the report only broadly advocates Pro/Rel on a very long term basis is probably the most damning thing that could be said. The reason its so damning is that DT or whoever is actually releasing the report to public neglected to publish the assumptions that they were operating under.
While there are certain lines that reputable consulting firms will not cross, generally the person who commissions the report gets to set the terms of reference/assumptions that the report will be constructed under. Firm's will use these assumptions even if the analysts creating the report don't necessarily agree with them, because hey you're paying us. This of course means that, by in large, a consulting report is going to say what the commissioner of the report wants the report to say.
So yeah, a report that was given its terms of reference and assumptions by a guy who is rabidly advocating for Pro/Rel is probably going to be biased for Pro/Rel. The fact that the report is so tepidly in support of Pro/Rel is very damning to my eyes. What this basically means is that under the most favorable, maybe even unrealistically favorable, conditions Pro/Rel is at best a project initiated in the distant future.
I say this all conditionally, since the assumptions the report was compiled under weren't actually released. So you have no idea why the report came to its conclusions.