Azure AD Sign-Ins should be available in non-AAD-Premium subscriptions
Customers not on AAD Premium P1 or P2 (i.e. Office 365 apps edition, Free edition), are unable to gain visibility into whether or not they have clients using legacy authentication. This is unfair, especially when you are now pushing the blocking of legacy authentication so hard.
The "Sign-Ins" feature should be included with all editions. This is currently setup as a sales trap.