Additional features, settings, or issues not covered by specific Microsoft Teams categories
Please check response from Andrew Hodges on the link below.
https://techcommunity.microsoft.com/t5/microsof...
Seems like we can arrange the files alphabetically temporarily only (while you're in the folder at a time). There's also a Uservoice post mentioned in the link above. You may opt to vote for it.
I hope this helps.