macOS Catalina beta release notes say “Future versions of macOS won’t include scripting language runtimes [such as Python, Ruby, and Perl] by default.” This means Catalina will have them but 2020’s macOS won’t.
Quoting myself from the New Mac Pro and Pro Display XDR Offer Power for a (High) Price thread:
It seems, rather than do a better job of supporting these scripting languages, they’re going to get rid of them entirely, Catalina will be the last to include them. I get it, few end users write scripts and those that do will install a current version, either directly from the runtime maintainers or via something like Homebrew. It also removes tools that hackers exploit.
Still, it’s going to be very disruptive to technicians who support many Macs, be a burden on smaller software developers, and greatly complicate the lives of users trying to make use of a vast corpus of code. That code is not just in repositories like GitHub or unmaintained binaries that assume the languages will be present, there’s also all the code that has been shared less formally on mailing lists and web forums.