Considering Safari 9 is in beta at the moment, anything is possible.
Exactly, which is why the suggestion to “turn off extensions” to prevent crashes and suggesting that Safari is working alright, is silly. If Safari crashes now then it obviously isn’t ready just yet. All you are doing is avoiding the issue and it’s not something an updated extension will technically solve, it will merely circumvent it, given that the cause of the crash lies with Safari itself. Not all extensions are updated timely after all, if at all. Safari shouldn’t crash because of extensions and if it currently does then it needs to be fixed and until that is done complaints about its crash-proneness are valid.