I don't know how to parse this comment. Why would the US give up on Taiwan "before it gets serious". If the US is involved in a shooting conflict in the Taiwanese strait, they either win or lose it conventionally but if it happens at all then nukes aren't getting involved unless mainland territorial invasions go on the table - and they're not going to.
The reality is the US would very much like to avoid having to negotiate that situation: far easier to arm Taiwan to the teeth with AA and anti-shipping missiles, and let them take care of it.
EDIT: It's also worth noting nukes aren't the only deterrent forces. It's one thing to "know" that the US Navy isn't going to get involved...it's quite another to conduct an invasion of an ally while well inside the missile engagement range of the US Navy on the assumption that's actually true.
The reality is the US would very much like to avoid having to negotiate that situation: far easier to arm Taiwan to the teeth with AA and anti-shipping missiles, and let them take care of it.
EDIT: It's also worth noting nukes aren't the only deterrent forces. It's one thing to "know" that the US Navy isn't going to get involved...it's quite another to conduct an invasion of an ally while well inside the missile engagement range of the US Navy on the assumption that's actually true.