I'd be willing to bet this is the case; this only covers 8.8.8.0 to 8.8.8.255 so not 8.8.4.4 so it wouldn't be that effective at blocking Google DNS; only 1 IP would be blocked.
Why would they be blocking it? Google promotes 8.8.8.8 as the primary dns server, and, as far as I know, as long as it keeps answering, clients won't fall back to the secondary 8.8.4.4.