The "interfering" this are describing is your framing. You want it to be interference in a legally actionable way, but it simply isn't.
18 U.S.C. § 1505 - Obstruction of Federal Officers (this includes ICE itself - obstructing or interfering with an ICE arrest is a crime)
18 U.S.C. § 118 - Obstructing, resisting, or interfering with federal protective functions
Those other two laws seem like an even weirder fit for the fact pattern in this subthread.
If "ICE vehicle has been identified, everybody go there" is followed by mobbing vehicles, blocking movement, inducing agents to disengage, or warning targets to evade arrest, that crosses from protected speech into actionable conduct.
See Brandenburg v. Ohio (https://www.oyez.org/cases/1968/492)