The entire world agrees bicycles are vehicles and it's encoded in the law almost everywhere. This is no true Scotsman, sure, but IMO if you're trying to argue a bicycle is NOT a vehicle you're only doing it to argue and flex your vast knowledge of the English dictionary to randoms on the internet. It's a completely unreasonable position to hold.
Many roads nowadays have a "one way only - bicycles excepted" to indicate the road is a one way road but bicycles are an exception to the rule and there's a contraflow bike lane. Most parks that have a no vehicles allowed sign is likely to have a bicycle excepted sign underneath.
Bicycles are vehicles and there is no ackshully that will change that. If you're trying to win an argument with the technicality that everyone would ignore a "no vehicles" sign on a bike that isn't an argument that disproves a bike is a vehicle. All it shows is that a bike is a special vehicle with special rules and exemptions to "no vehicle" signs.
There is no pedantry in calling a bicycle a vehicle. It's obviously a vehicle - it's entire purpose is to be a lightly-mechanized means of transit! Now if we see a sign in a park that says "no vehicles" many people - using our cultural knowledge and context - will interpret the intent of the sign as a reference to "[motorized] vehicles".
Those people are wrong. It's as simple as that. In the eyes of the law bikes are vehicles nearly everywhere. It's settled and not up for debate or discussion.
I believe the entire point of the exercise is to demonstrate people will argue that the sky isn't blue.
I think the point of the game is to demonstrate there are some people who will argue the sky isn't blue. That is one thing we should all be able to agree on but if you were to pose that question to the internet you'd definitely get "I'm colorblind and what you call blue I call green ergo the sky is not blue".
Those people aren't worth your time and will disagree just for the sake of disagreeing and getting a rise out of people. I'll admit I'm guilty of doing the same in some circumstances.
Really what surprises me is how few people seem to understand that language is incredibly fuzzy. That there's an imperfect encoder (language) and decoder (listening/reading) system. That people are working off of different priors that bias these systems. That we aren't perfectly aligning the intent of our messages with the reception of them. That this system becomes even more fuzzy as the audience increases (increased variance in priors). It is a bit more surprising to me that in a community full of nerds where we communicate online, where we're exposed to many priors, that this is still a relatively unknown phenomena despite it being fairly easy to conclude simply through experience (besides also being fairly well discussed). I for one think the fuzziness of language is incredibly cool.