Because they believe that they are free and kind of are

Well the secret bosses have a lot more symbolism regarding freedom than the flowers

And the flowers are far from free

i was gonna say the same thing, they're in constant life danger, and if it wasn't for asgore they would died

but that's the same for gerson.... uhhhhh.....

gerson is free because he is free of the fear of dying, he is already dead, so he doesn't have to worry about death

also what makes pink free? she's trapped inside herself.
and spamton? he never thought he was actually free, altough that's something he was looking for
and what about the trashy trio? they had a life elsewhere, but now they're in castle town
the mikes have the freedom motif, but why? they're trapped in a role that probably originates from something much bigger than all of them
jevil is the only one i see fitting with the freedom motif

pink, I think its that she found a body and now she is free to go anywhere with it. spamton wants to be free from being a simple little puppet,

Don’t the flowers say they have freedom n’ [@!*$]

they're stuck in plastic tins for the rest of their life what do you think
Also it has to be directly tied to freedom, not just stuff like the flowers there. Like jevil has false freedom, meaning he believes he's free. Spamton is the opposite, he wants to be free but knows he cant. The knight in this example, will supress freedom of others, Like how they kinda just killed flowery. Gerson is truely free, as he's perfectly fine with what he has, and believes we can be free. Pink, as sproit said, is trapped inside herself and ends up content with the state of Her and The darkner herself, Atleast from what i can see when i played for the chapter for the 1st time

The knight doesnt have the freedom motif beacsue of this, it supresses freedom of others. The others either have their own freedom or encourage it.

the trash gang i have absolute NO f*cking idea
For funny i guess