Tomahawks can operate fully autonomously with no substantial loss of functionality. Indeed, picture a swarm of one, and you're operating in this mode. The missile commlinks serve to enhance the missile's effectiveness; they are not the sole source of its effectiveness.

Here's something for you to puzzle over:

Your missile has up-to-date topographical maps of an area, and as-up-to-date-as-possible maps of all known anti-missile sites in the area. Thing is that you're not going to know about all of the anti-missile sites: many sites are portable (thus they move around), and some remain offline and nearly impossible to detect until enemy command determines that that site can kill a missile.

If your missile doesn't have commlinks, how do you tell it to avoid anti-missile sites discovered after the missile was launched?

Additionally, a careful reading of the comment that you replied to will reveal that the Tomahawk has -since the 1990's- been a fully autonomous missile fully capable of flying a pre-determined path to a target. Indeed, that is the least interesting part of the missile's capabilities. In short, we've had "self aware" warhead-tipped "drones" since at least the 1990's.