Does lenovo thinkpad tablet 2 get windows 8.1 update?

You should go to window update option in control panel and then you should select window update automatically. Then press apply and ok button.
There's nothing try to do anything, if update is necessary of your thinkpad then that will update automatically.

Yes, if update windows 8 then windows 8.1 automatically update.

If it has Windows 8.1, it can automatically update to Windows 8.1 Update…

Yes, update it by going to the windows update option