There’s been reports of mastodon links being handled oddly for a while prior to this announcement. Not insta though. Odd Twitter considers them a competitor though Insta did get big through twitter originally.
For a while? I've only heard of that in the past few days.
If by "a while" you mean the past handful of days, then yes. To suggest that this has been an unspoken policy for years is simply wrong and misleading.
I more mean “on various occasions over the last several years”