Right after match you willbe able to see game stats in your match history, this is how I thought it supposed to work, but when you open your Overwatch Profile ingame and open History, then go to Game Reports section and select last game report and view it with button View Game Reports the select Teams tab and there is completly wrong stats, like 0 kills, 0 assits, 0 death, 700 dmg and so on. I assume it happens after game restart, but anyway it looks incorrectly, i mean if data got deleted it should not be displayed at all and there must be notification that you can see the data only in one game session scope, and it wipe after game close. And also I do not see any reason why it must wipe every game client restart, it could be cached in game files and wipe every season, it wont take much space. I report it as bug because it lookg broken and unfinished part of Overwatch 2.
I can confirm that the team stats some time get broken even without reopen game client. I had experience today to view Team stats in Game Report right after game and it was display incorrect values there.