I think there's at least some truth in that. I mean, we already had 2 CM-youngsters that season with Pogba and Marrone (who was rather highly rated at the time and homegrown, so we wouldn't have discarded him), I could imagine the management deciding against a third, especially an expensive one, as there wouldn't be enough playtime for all of them anyways. Add to that of course that PSG would have probably matched any offer we could've made anyways, seeing as they didn't have any reason to care about FFP back then.
It's still a hige opportunity missed by Marotta, but an excusable one imo, especially considering his other brilliant signings.