I understand you can get the new drivers here
Don't get too excited though, the opening line reads:
We are excited to announce the hotfix release of the Microsoft Drivers for
PHP for SQL Server. The SQLSRV and PDO_SQLSRV drivers have been built with PHP 7.1, 7.2, and 7.3
and tested on all supported platforms.
I know that support for MSSQL drivers has ended but whether this continues into v7.x and later PHP releases, I don't know. The PHP site notes on MSSQL are not encouraging. Better read the documentation carefully.
I would suggest this is an indicator that the Dark Side is going to jealously guard its proprietary property in future and will not allow third party programs access to its tools. You may be wise to consider opening negotiations with your host or network administrators or masters in whatever your situation is and alert them to the likelihood or possibility of a total disconnect between PHP and MSSQL. I understand that Moodle's support for MSSQL is strictly limited already, but if I am wrong, I would be happy to be corrected. I don't think that adding a MySQL or MariaDB10 or PostGreSQL would be called a "change of platform" just an additional DBMS. Good luck.
Also, I anticipate that just as with AWS and GoogleCloud services, et al, the next version of Windows will have more in common with Chromebooks than as a stand alone system, Azure over alles I suspect.