We have a current setup where we have two SQL 2008R2 database servers in production. Our reporting team requested a single place they could query data from both servers (to avoid both hitting production directly and the performance issues with linked servers). So we set up log shipping where we ship several databases from both sources to a target server. It works great, the databases on the target server are read only during the day and only unavailable when the log shipping restores are scheduled at night. However, the vendor applications for both source servers are going through an upgrade project, and they will unfortunately have to be be different versions (SQL 2014 and 2016 respectively).
Most of what I have researched seems to say that you cannot log ship from a different source version, but I've also found information suggesting that you can ship from a lower to a higher version, but am unable to find anything official.
So, my question is, is it possible to log ship from both 2016 and 2014 sources into a 2016 destination, AND leave the databases read only when they are not restoring? And is there official Microsoft confirmation of this?