A larger standing army is unlikely to ever come back unless the US specifically instructs Taiwan to do so. politically it is a non-starter, and militarily it is expensive to maintain a larger army, therefore taking resources away from air force and navy.
Taiwan is going the way of having a large reserve army, though I question their effectiveness in battle, or whether they could be stood up at all. now another question is whether a reserve army can potentially lead to a operation valkyrie type outcome. after all, an officer assigned to lead reserve units is unlikely to be one in anyone's favour, and reserves forced to fight are more willing to see a swift end to the war.
Operation Valkyrie is an interesting event.
But in all likelihood, I reckon we're more likely to see professional soldiers organise a Valkryie.
Look at how many retired Taiwanese generals are being called out for having too many contacts with China.
And this retired general in Taiwan made waves by openly calling for active-duty generals to do a Valkyrie against the DPP politicians.