They easily could, but even I think it's a bad idea to pay Okung $12M/yr EACH of the next two seasons (I believe he'll have all his guarantees by 2019, so we could cut him then at no cost; still way too much.) Just because I rant about spending big on an OT the first lukewarm body we find.
The reason I didn't expect him back is because his option hits in ~2½ weeks, which left little time to hash out a new deal before then and there's NOW way we exercise that option for what he delivered last year. Unless they've been quietly discussing it since the season ended (or earlier) it's not happening.
For all the talk about "well, he's the best we can get, so 'worth' 2 years at $12M each," that's just not how Elway operates (and in this case, thank GOD it's not.)