Haha, I do love me some thumbnail speculation. 
About where the gun is pointing - it seems passable according to these guidelines
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For the longest time I’ve seen Fishsticks + Jonesy etc in thumbnails and was under the assumption that Epic was ok with it.
As of June 27, 2025 there is a new subrule in 1.7
* 1.7.1 Epic-Owned IP. Epic owns intellectual property (IP) rights in all of its original creations. You may use Epic-owned assets made available to you in UEFN in your island. However, you may not use recreated or otherwise obtained assets, maps, characters, music etc., from Fortnite or other Epic-owned properties without permission, either in your island or its metadata. For example, you may not recreate Battle Royale season assets in your island or metadata if they are not made available in UEFN.
So, I’d try to submit a version without any of Epics characters.
But I think there is a bit more nuance here. What if someone uses the NPC device to pose a character and uses that in a thumbnail? The 3 characters you show seem to be ripped from artwork. (Verifiable with reverse image search) - So If you’d like to include characters in your thumbnail, try posing and capturing them yourself.