The career profile has been broken far more times than just twice. Sometimes it incorrectly displays totaled stats, or it incorrectly merges previous season data with current season data, or it doesn’t update data after playing, or it loses data after playing, or its straight up blank or missing. The possibilities are truly endless.
You can read more about these and other issues in my thread Comprehensive Thread Of All Top 500/Competitive Bugs under: Incorrect Competitive Career Statistics Page.
As for the deletion of old statistics, I don’t think that’s the case otherwise there would have been absolutely massive backlash. I think those stats are just now only accessible by the Developers and not the players, which I do not agree with in the slightest.