but all the sites we still have on the list of former T-sites were not subsumed.
But many of the sites on the current T Lists DO include smaller sites which were on previous T Lists and are now subsumed so the attrition you referred to in the first post has been less than might at first sight seem the case.
Regarding "Former T List" sites (which exclude those known to have been subsumed) - you have listed some of the reasons. I guess each country needs to be looked at individually to try to assess the reasons
If we look at Libya with 7 "Former sites" and no Active T List at all. Again it is unfortunate that we don't have immediate access to the year in which they were removed but I would look at them and conclude
a. For various political reasons Libya wasn't interested in going for more WHS from the 90s onwards. It ceased being a member of the WHC after 1988. The last few years haven't exactly put it in a better situation either!
b. There are a large number of those now removed which would have been being nominated as Greek/Roman sites. I have visited Apollonia and Ptolomais - I guess Apollonia could have been justified as an extension to Cyrene with which, as its port it was inextricably linked. One might expect that a nomination of Cyrene today without Apollonia might have been criticised by ICOMOS. But the 1982 AB evaluation makes no mention! As I rmeember the site its "best" bits were mosiacs which had been lifted and were either on show on site or in the museum in Tripoli
c. Regarding Ptolomais, Tocra and Eusperides - yet more Roman sites. I guess it might have been the case that UNESCO/ICOMOS might have liked to have seen the full set of the Pentapolis nominated but how many roman ruins should the List have?
d. Ghirza is another "Roman" albeit away from the coast. The same question applies
e. Germa would have been a "Roman period" site of the Berbers - I guess it could have been worked up - but was Gaddhfi that interested in "Berbers" and the Fezzan other than for the oil and water?
f. Tripoli is a strange one. We visited and may not have been taken to everything of significance but in terms of cultural remains I know of nothing much
g. Medin Solton I can't find either on the Web or in Lonely Planet!!