No, it was because the security model changed.
It was Apple’s choice for Yosemite because of security but the workaround was disaster prone.
I sure you understand Trim. It’s essential to a long life for SSD’s and garbage collection is not the same thing.
Besides they fixed it later on.
Trim allowed some third-party SSDs that were not OS X compliant to work on Macs. Apple did not approve the use of such third-party SSDs for various reasons, one of which is they tended to slow down after extended use, while the approved models did not. TRIM solved some of that issue, but even with the use of TRIM the models would slow down. . . Because they, and it, were kludges. Apple found a way to bypass the kludgy nature of those drives in OS X.10 Yosemite and implemented it that worked with all SSD drives, it did not "break" TRIM, it deliberately bypassed the need for such a kludge. You are the only one who is talking about "garbage collection" pretending you know something useful. PAY ATTENTION.