HKHostFreezeCkptTrimming on SQL Server 2017
I don't have an answer for what exactly they mean, but I see them on every machine where I have a memory optimized file group.  

Since they start with "HK" they seem to be related to In-Memory OLTP (codenamed Hekaton prior to the production release in SQL Server 2014).

I would say that since they are INFO messages, and they are common on instances with memory optimized filegroups, that they are nothing to worry about.

There isn't currently a documented way of disabling those messages, and I hear that there really is no undocumented way of disabling them either.  There is a precedent for disabling backup-related info messages (see trace flag 3226), so you could make a request on user voice: SQL Server Uservoice