@PeterForster
Have you gone through the article?
Yes, but it seems that you don't. There is NOT another "New Outlook" for Personal Accounts and other for Business/Enterprise. Can you find the two? What is the full name of each of them?
There is only one New Outlook. Only One. When Microsoft introduced it in September 2023 it was so basic and crappy, with so little functionality, that they only made it available for personal accounts and support only for that. It didn't support Exchange, it didn't support offline mode, and it didn't support almost any of the features that businesses use, so it couldn't support it for Business/Enterprise.
Now that they have added offline mode, Microsoft introduces the same "New Outlook" for use in Business/Enterprise and supports for that, even though it doesn't support Exchange On-Premises accounts, cached mode and is still the same garbage as before. But it's the same New Outlook. With the same shortcomings. It's not even really ready for personal accounts, but Microsoft has to meet a schedule to drop classic Outlook at the cost of screwing their customers.