Nope, there's nothing weird about it. The plan for months has been for Cena to get Brock over and make him seem utterly unbeatable so that they can pass the torch to Roman Reigns and have him beat Lesnar at Wrestlemania with an absolute ton of buildup and hype. Sorry to let the cat out of the bag if you'd rather not know, but this is all a big plan to make Rock's nephew the next great one. It's common knowledge on wrestling podcasts, etc.
Don't follow a lot of the pods/commentary (besides Grantland and random Yahoo/Bleacher Report stuff), but that falls in line with what I thought would happen before the match, though I definitely didn't think it would be a squash. Reigns is going to be in line for the eventual title match for Wrestlemania, that's logical. However, I think they need to be careful with how predictable that plan is. As Lesnar's win against Undertaker was so effective because it was unexpected, another poor Cena showing would be just as ineffective due to the inevitability of it.
The other issue is that Cena is not a traditional top face in that a lot of smarks actually root against him. That combined with the fact that Heyman is so on his game right now is why people were actually cheering for Brock during that match and a lot of the promos before/after. If they're not careful they're going to turn Lesnar into a face during this program which might start to solidify. Heyman's mic skills are just too entertaining, especially when contrasted with Cena's bland and well-worn "never give up" cliches.
I accept that Reigns eventually will be the one to win the belt from Lesnar (he already beat Orton, what other top heel is there to win it from?) but I would love for it to be less predictable scenario. For instance, let's say Bryan didn't have to have Tommy John surgery and could be back in a few months. They could have done some scenario where multiple faces are vying for a shot at Brock.
The trick in storytelling is to get to the inevitable conclusion in an unexpected way. But hey, it's wrestling and things change all the time. People get hurt, or feuds/wrestlers don't get over as expected. I just think that this Cena/Lesnar feud will not have the expected effect the WWE is looking for.