I don't see that as a particularly good deal for Edmonton.

In terms of veteran salary dump, Sekera is cheaper and under control for one fewer year than Ryan, so Edmonton is paying way money. In total the Oilers would pay an additional $12.5M. Of the two players I think Sekera is probably the more usable player for Edmonton as well.

I'm going to just assume that there is an extension attached to Karlsson as well even though you didn't mention it. Let's say Karlsson signs for the 8 years $11M that gets thrown around a lot. That means that over the 7 years that both Draisaitl and Karlsson would be signed the Oilers would be paying an additional $13M in cap space, not to mention $22M extra for the two additional years of Karlsson's extension (2 years that likely he won't be meeting value). That is a ton of extra money to go from a 23 year old star center to a 28 year old elite defensemen.

I know there is a price to be paid for an elite defenseman like Karlsson, but I just can't see giving up Draisaitl and his favorable contract. There is too much extra value in there for the Oilers. I don't see how this deal makes Edmonton better because of the dead weight of Ryan and all the extra cap dollars Edmonton would lose. In addition while minor they have to give up a prospect and 2 rounds of value in draft picks.