Are Users with a Teams Premium License no longer able to sign into a Teams Device (Logitech Rally)?

It is not allowed to sign in to MTR systems with a user license any more. You need a room license to sign in to MTR devices.

https://learn.microsoft.com/en-us/microsoftteams/rooms/rooms-licensing

User licenses aren't supported for use with meeting devices. User licenses that have been assigned to teams meeting devices need to be replaced by an approved Teams Rooms license prior to July 1, 2023. Meeting devices that do not have a Team Rooms license after July 1, 2023 will be granted a 90-day grace period ending on September 30, 2023. After the 90-day grace period, devices will be blocked from signing in until a Teams Rooms license is assigned.

Also, Microsoft Teams Shared Devices licenses aren't supported on and won't work with Teams Rooms devices. Teams Rooms devices should only be assigned Teams Rooms Basic or Teams Rooms Pro licenses.