In matomo-org/matomo#13596 / matomo-org/matomo#12785 we add support for matomo.php as endpoint besides piwik.php. It will also be the default for new installations.

The log importer needs to be adjusted to support replaying those requests when using eg --replay-tracking. It isn't that trivial since we currently can only specify one --replay-tracking-expected-tracker-file=piwik.php file but people might use both piwik.php and matomo.php. By default, the log importer should check for both files.

As for the _record_hits method, we maybe still need to use piwik.php as tracking endpoint until Matomo 4.0 as it could otherwise break the import for existing users. We could set it to matomo.php and hope that if it breaks, users don't automatically delete log files so they can fix the issue and replay again after making matomo.php accessible. But realistically, users might only notice after few weeks that it broke and by then the log files may have been deleted. It's tricky. Maybe we could record into matomo.php by default, and if there is eg a 404, or 403 error, then we track into piwik.php?