Hi,
I talked about a bit here:
The main point is: This is unnecessary and redundant in HTML5 and therefore for far over 99% of all users. But the thing is: For a tiny fraction of users (e.g. those using IE8 and older) this is needed as otherwise the browser doesn’t know which language the <script> is.
If you don’t care about those ancient browsers, you can definitly remove the type=, but removing it for everyone in Matomo is a bit harder.
I guess it should be done the day matomo.js doesn’t support those browsers anymore.