Using Outlook for Android in business environments for email and scheduling
Regile
This is also happening in IOS
Perhaps you didn't notice that this thread is called "Outlook for Android opening links in internal browser", and it's posted in the "Microsoft 365 and Office / Outlook / Android phone & tablet / Office Mobile apps" forum?
You can find the correct forum for asking about issues with iPhones and iPads at this link: https://answers.microsoft.com/en-us/msoffice/forum/msoffice_outlook-mso_imobile-mso_mobapps
You're also replying to a post that is over a year old ("In reply to Regile Reb's post on July 9, 2020") about an issue that Microsoft issued a fix for in November 2020, over 9 month ago.
Microsoft also explained their rationale for this "feature", and it has nothing to do with tracking user activity in browsers, (they don't need you to open a link in an email to know what the link is, and this "feature" doesn't tell them anything about all the other browser activity that you do when you're not reading mail). Their rationale is that opening a link in an internal browser is less intrusive to your work flow because it doesn't involve a shift in focus to a external app. That might actually make sense for certain types of users working within an authenticated Enterprise Domain, but it doesn't take account of the needs of all users. But just because it doesn't take account of your needs doesn't mean that it's doing anything intrusive - you really aren't that important.