wtf are you even talking about?
whether taiwan is a member of the WHO wasn't the point. the point is
the WHO and all western governments were well aware the pandemic risks in january and did absolutely nothing for 2+ months. they were doing nothing to stockpile medical supplies or build ICU centers, they were actively telling people there was no risk, business as usual, no quarantines, no social distancing, telling everyone
not to wear masks, etc.
in hindsight we now know that western governments literally did everything wrong they possibly could have.
and since when do we trust everything the chinese government says anyway? china says "trust us" about urgent matters of national public health, and all western governments oblige,
Make up your mind

Should we have trusted what they've told the WHO or not?
you are the only one saying we should have blindly trusted china.
studies showing human-to-human transmission in january were
independently verifiable. it was not a matter of trusting china.
https://www.medpagetoday.com/infectiousdisease/publichealth/84537western governments in italy, USA, and elsewhere simply ignored the threat for months and fed their populations endless misinformation.
at most, you can blame china for delaying reporting what they knew until mid-january. they did the same when the SARS outbreak occurred so it's not a surprise. they are a propaganda machine after all. they need time to get their house in order.
but how does that excuse our governments for ignoring the threat until late march? the USA and south korea confirmed their first coronavirus cases on the same day. the USA is projected to have a ~1000x worse death toll in spite of korea's much bigger population density. you want me to blame china for that too?