I just did this upgrade last week (10.5.1 -> 2019.1.2) without many issues. I was able to follow this guide without issue. Upgrade from Tableau Server 2018.1 or earlier to Tableau Server with TSM - Tableau .
Issues I did run into:
- File permissions - make sure you have appropriate Windows permissions for your run as account / Network Service Windows account.
- Warming up external query cache errors - 'Warming up external query cache on data change' Error - How to identify the problem and move forward.
As always, attempt the upgrade on a non-prod instance to make sure you know how to work around any issues with your environment.