This might actually be a game bug, in mod.class.interface.Combat:isUnarmed():

-- Check if actor is unarmed
function _M:isUnarmed()
        local unarmed = true
        if not self:getInven("MAINHAND") or not self:getInven("OFFHAND") then return end
        local weapon = self:getInven("MAINHAND")[1]
        local offweapon = self:getInven("OFFHAND")[1]
        if weapon or offweapon then
                unarmed = false
        end
        return unarmed
end

I'm not sure what the "right" answer is for whether a character without a mainhand or offhand slot should be considered capable of engaging in unarmed combat (there are certainly enough armless addon races, after all), but as we see above, the game currently says no, and since all the Wyarm Combat talents are flagged as 'is_unarmed', mod.class.Actor:preUseTalent() blocks the player from using them ("player can't use this talent while holding a weapon or shield").

The easiest workaround would probably be to superload :isUnarmed() and add a special case for Wyarm. I've had success with this code, for instance:

local super_isUnarmed = _M.isUnarmed
function _M:isUnarmed()
  local evo, ok = table.get(self, 'descriptor', 'class_evolution')
  if ok and evo and evo == _t'Wyarm' then return true end
  return super_isUnarmed(self)
end

Hello! im sorta new to this game and have only recently gotten some clears on insane and stumbled across this. I know there's a really good mindstar for wyrmics and being unable to use it alongside the class evolution feels bad. Was there a numerical reason why we lost access to weapon slots? Was the class tuning that tight?

anyways I love great wyrarm focus its sick af.
I'd love to see more combat talents added, maybe the unarmed tree with combination kick or a reflavoring of it to give the class a way to strip sustains?
not being able to get enhanced manaclash or rune of dispersal in embers of rage has made me feel the need for that on 'weaker' classes compared to paradmox mage