Samsung did the same thing with the Oreo beta. I was on the beta and then the final release while most were on 7.0 and as now that's where people wewrew stuck until Oreo rolled out. Nobody on Sprint anyway got the incremental version updates.
ETA: this is in response to :"
Re: Samsung S9 Pie Beta
Before talking about the Android 9 Beta Pie to start rolling on our phones,let's ask ourselves why till now Android 8.1 Oreo isn't available in S9 and S9+ devices?"