I think the Cross deal will get done, and with the 5th year option + potential for the tag thereafter it is relatively clear cut what that term+$ will ultimately be for a player of his youth at that premium position. Less urgency to get that one done.
I think the variance in outcomes for Abe this season is reflected in the relatively short 3-year term. If Abe had remained unsigned, and stayed healthy all year, and played to his pre-injury standard you're probably look at just under top tier Sewell type money in the RT market. Seahawks mitigated that possibility with this extension by taking on some possible injury risk. Whereas if Abe's injuries are behind him, the 3 year term allows him another chance at a bigger extension in his prime. The length reflects give and take on both sides, and makes a lot of sense. 3 year steal if healthy though.