In fact, they're already planned for this weekend. See the map below for the one closest to you:
SwampYankee
joined 4 days ago
https://www.law.cornell.edu/uscode/text/10/12406
Orders for these purposes shall be issued through the governors of the States or, in the case of the District of Columbia, through the commanding general of the National Guard of the District of Columbia.
As Newsom stated in his letter, the order was not issued through him, therefor not pursuant to the law, or in other words, illegal.
If the Feds are willing to illegally federalize National Guard troops, and the National Guard in any given state is willing to obey those orders, it tips the scales significantly. States need to start taking measures to ensure their National Guard is truly under their control. These are the "well regulated militias" referenced in the second amendment, and if they are subject to the whims of a federal tyrant, then the second amendment is moot.
Well, Newsom is suing which is... fine. I think he should deploy his remaining 20k troops to kick the (4700 and counting) feds out, but that's playing with fire. Going forward, as I suggested, states need to make sure they control their Guard deployments. This could take the form of legislation or executive orders at the state level, or, since it's already federal law that the orders go through the governor, a simple memo informing the Guard that anyone from command down to rank & file will be immediately arrested for following illegal orders.
And on your other comment, yes, by the letter of the law that was illegal, although it was a slightly more complicated situation because as the article states:
... then Faubus reneged on the agreement.
Whatever. Right now, in the time that we are currently living through, during which an unhinged aspiring dictator is deploying military forces on US soil for immoral reasons, is not the time to equivocate about legality.