That message is maybe a bit confusing, but what it means is the following:
The version of those two plugins you have installed are not compatible with Matomo 4 and therefore have to be disabled during the update. But there are newer versions of the plugins that are compatible with Matomo 4 (and only Matomo 4) that will be automatically installed during the update, so you can use them just like before.
For those two specific plugins it is a bit more complex as Provider was a core plugin in Matomo 3, but is not included by default (only on the marketplace) in Matomo 4 and CustomVariables still works, but you should probably use custom dimensions instead: https://matomo.org/faq/general/faq_21117/