In good French, you must say [tro.po.cu.pé] and not [tro.o.cu.pé]. The liaison is an essential characteristic of the spoken French language. Though in the present day, with the cultural debasement, the liaison is often omitted, it is incorrect to do so.
We even add phonetic letters to create a liaison when we feel it is missing, as in the expression "va-t-en": [va.t(en)] the "t" here is only added to prevent the ugly proximity of "a" and "en".
Today, with the advertising industry, spoken French is deliberately damaged, as in ads you will always hear "vingt euros" pronounced [v(in)(eu)ro] instead of [v(in)t(eu)ro]: And still, noboy will ever pronounce "vingt ans" as [v(in)(an)] but everyone says [v(in)t(an)]: In the same way, everyone should say [v(in)t(eu)ro].
Though eminent writers told the advertisers it was a mistake to say [v(in)(eu)ro], they carry on doing it, because they think people are not smart enough to understand the liaison. I believe they are not smart enough to understand people are not as stupid as advertisers think they are...