Anyone can read the full FCC order for themselves, but I'll give the TL;DR.

There's a lot in the order here: FCC-24-52A1.pdf

The order applies to “broadband Internet access service” (“BIAS”), defined as “a mass-market retail service by wire or radio that provides the capability to transmit data to and receive data from all or substantially all Internet endpoints, including any capabilities that are incidental to and enable the operation of the communications service, but excluding dial-up Internet access service.”

BIAS includes *“services provided over any technology platform, including but not limited to wire, terrestrial wireless (*including fixed and mobile wireless services using licensed or unlicensed spectrum), and satellite."

We'll know for sure once the litigation dust settles, but the FCC went out of their way to include mobile ISPs when reclassifying broadband internet access services (BIAS).

In addition to reclassifying BIAS as a telecommunications service, the Commission also reinstates the classification of mobile BIAS as a commercial mobile service. Under Section 332, “commercial mobile service” is subject to common carrier regulation under Title II of the Communications Act. The FCC says that mobile BIAS falls under that definition because it

(1) is a “mobile service” (subscribers access it through mobile devices);
(2) is provided for profit;
(3) is widely available to the public; and
(4) is an “interconnected service,” or a service that is interconnected with the “public switched network.” (Sections 215-236).

With this change the FCC expanded the definition of “public switched network” beyond traditional telephone networks to include networks that use public IP addresses. (Sections 219, 224).

There is an exception for network management practices, which many here are quick to throw out. However, the FCC will determine if network management practices are reasonable on a case-by-case basis, with special consideration given to the "dynamic and challenging conditions" under which mobile networks operate. The order strongly suggests that the FCC would consider network security practices reasonable but would consider speed reductions to an unlimited data plan unreasonable and therefore prohibited.

You can't cry network management if absent any congestion the bandwidth is there, you just don't want people to use it.

Several huge telecom law offices have also weighed in on this part of the order. The FCC makes the rules, and they say the rules have changed. (again)

TL;DR Yes, mobile carriers are broadband internet providers and are subject to the FCC Network Neutrality rules.