In your example where literally every detail has been changed, including the type of product being produced, that makes sense.

The video says, "Portal Revolution Official Trailer." What that says to me is "This is the official trailer" presumably released by the creator of Portal Revolution (which is a community mod).

Even in the worst possible way I can try to interpret that, calling it "manipulative" seems like a huge stretch.

If Valve somehow thinks it's the same thing as your Pokemon example, I'm sure we'll see some action taken.

Not my job to make your argument for you. I made my response based on what you said. If you want to reword or emphasize something relevant go ahead. Otherwise it just sounds like "No, you, um totally misunderstood me! Ya, that's it! I'm not going to tell you how though, just keep re-reading it until you agree with me!"

Trademark is not ownership of the word. Anyone and everyone can use the word "Portal" to speak about the game, its mods, its lore, fan content, likes and subscribes, etc.

The video was originally titled in the already common pattern across all industries in the media: "Work title: Work subtitle - Official Announcement". It's honestly not hard to parse, and it does not constitute in itself any judgment on whether it's Valve's Portal or the Portal of anyone else who can and is allowed to use the name (think eg.: I write my college thesis and announce it as "Portal: Why the Game is Good - Official Announcement").

I do be fair and mention I come from the Pokémon fandom, where (until the series went into Yearly Crunch) the amount of fan content more than 7x-ed the amount of "official media" so one learns to parse announcements and titles faster. I guess I'm trained by a different internet than yours. However I don't get why you think I'm somehow "flinging insults", but I guess that just strengthens my point that elementary education should be revisited.