I don't think the other commenters are giving you the whole story. Read the suit. The specific injunction sought under "arbitrary and capricious" is that the FCC is failing to uphold their responsibility based on a 2016 court ruling which pivoted on the decision that classification broadband as a Common Carrier should be upheld - NOT Title II itself. What concerns me about this is that even though they do seem to have a valid argument, if you read the ruling on the case in question[0], it pivots on the court's understanding of Common Carrier. And the court's opinion is not a simple statement of fact. The issue is explored with nuance and deeply wedded to a discussion of anti-trust issues, which is why I remarked elsewhere on this discussion that the FTC should be compelled to step in if abuses happen, which is what sitting Chair Ohlhausen has publicly committed to do[1]
[0] https://www.cadc.uscourts.gov/internet/opinions.nsf/3F95E491... [1]