just as a quick devil's advocate- there are scenarios where a user will deliberately block google DNS at router level ( one such is when a user trying to outsmart NETFLIX geo restrictions, because the netflix apps are hard coded to call up google dns and go
aha- we know where you really are). some Roku devices are also hard coded to do that.
So some vendors of smart DNS advise their customers to put hard blocks on 8.8.8.8 and 8.8.4.4 in order to get multi region netflix etc. working
anyone with such a block could be missing out on newest sigil updates. because sigil will conclude there is no reachable google dns and therefore no internet (
heck, they may even still have book view working 
- just saying )
i see no need for changes, but this thread may help explain the next obscure
sigil cant find updates complaint..
googling "block google dns for netflix" will show that it is a popular query and bring up various references