There are some things to consider, that I can think of:
Yes, Microsoft broke some APIs that rendered new installs not working. (you could not get federated setups to work anymore.) However already configured environments should not be affected. (look in the forums). The new app has been released for UCS 4.4 like last week or so which specifically addressed this issue.
During the O365 connector setup you had to import a certificate into Azure AD and that has now changed. You will have likely need to re-upload the new certificate as shown in the O365 config wizard in the UCS O365 connector app.
In order to login on Azure AD and Office online while the federation is broken, you will need a user that is not federated and only exists Azure AD (not in your UCS domain). Such users are identifiable by their user principal name suffix (username)@yourazureadtenant.onmicrosoft.com.
This user needs (AFAIR) global admin privileges on your Microsoft Azure AD tenant. Your very first user that you have created, should be such a admin and will not be redirected to your UCS SSO page.
If you have gone through a partner who has set up your tenant initially, they might be able to access your tenant and add such a global admin. - Keep these admin credentials in a safe space