First of all, congratulations on the good news for your colpo & biopsy! False positives happen all the time, but at least they are better than false negatives... It is not surprising that your Pap came back abnormal for no reason: during menopause, benign epithelial changes take place in the cervix. These changes all too often get picked up as "dysplasia" by Pap tests, esp. ThinPrep. The problem with ThinPrep is that although its sensitivity is higher than that of the conventional smear, its specificity is not.
I am surprised that they told you that HPV testing happens with HGSIL or higher... I am pretty sure that the opposite generally applies, i.e. they check for HPV only when they find very minor problems, e.g. ASCUS. For mild dysplasia or higher they do not bother to test for HPV, they just assume you have it... (It sucks, I know!).
In your age group it is highly unlikely that you have HPV. If you want to make sure, you can always ask them to do a test, for instance, when you next go in for your follow-up smear. The process is the same, they will just take an additional sample. Besides I have read in the literature that HPV testing should be done for women over 35 because many of these women are NOT infected and their perimenopausal changes are all too often misclassified as dysplasia. Go figure...
All's well that ends well! I am very happy for your good results. Please wish me luck with my colpo next week... (I was relieved to read that yours did not hurt at all.)