It was announced last August, in one of the macOS Mojave betas. The function Back to my Mac which was removed in macOS Mojave, will no longer be available in all versions of macOS starting next July.
The information is in an update of the Back to my Mac support document, where they notify us that users will stop enjoying the function from July. By not making any specification about which operating systems are affected, everything seems to indicate that it affects all systems that support iCloud.
If we resume the communication from Apple in which it announced the suspension of the service, the company offered us alternatives. Today, iCloud file synchronization works perfectly so it is more viable to use iCloud Drive, in the same way as other cloud storage services. Another alternative may be to use the shared screen o apple remote desktop. Maybe our suggestion for an average user is to use iCloud Drive and screen sharing. Everything seems to indicate that Apple's remote desktop is not up to date, since its last update dates from 2017 and does not receive good ratings.
I use iCloud Drive file syncing on a daily basis, leaving my documents on the same desktop and it's wonderful. The screen sharing option is perfect for managing a Mac in another room. For example, I often use it to play multimedia content from my Mac connected to the television in the living room.
Apple's decision can be seen as an action to make iCloud profitable with your subscription plans, with the following capabilities. But it can also be seen as the closure of an application from the past, when today content is shared with a large number of cloud services. Be that as it may, Apple's decision is made. In the document it indicates the following:
As of July 1, 2019, the Back to My Mac service is not available in any other version of macOS.