The problem is that fair use and satire are defenses that must be argued. They don't automatically stop you from being sued. It can results in a lot of upfront costs and hoops to jump through before you are actually granted your fair use exception. You have to be pretty committed to your joke to actually fight something like this to the end.

Although if I were Comcast, I would ignore this entirely. I wouldn't want to risk the Streisand Effect bringing attention to this type of thing.

You can't ignore a trademark violation and keep your trademark. Trademarks can become "generic" (think Kleenex or Band-Aid) if not enforced, which makes them unenforceable. So no, they won't ignore it.