I can only hope its only a company merger and not a software merger.
Well, I think your hopes are dashed. At least according to that admin's post where he says,
...we determined that the Avira engine would fit naturally into SUPERAntiSpyware... . As such, we made the decision to increase the protection of SUPERAntiSpyware by combining the powerful Avira engine with our own native engine.
This falls in line with my own experiences and observations over the years with past mergers and acquisitions. That is, typically when such events happen, 1 of 2 things occur. Either [hopefully the best] code from each product are combined into one new product, or one product is killed off completely (thus eliminating the competition).
From a business aspect, it typically makes little sense to maintain development and the necessary logistics to produce and sell two competing products. To be sustainable, the market has to be HUGE and brand loyalty unshakable. Even GM eventually came to the same conclusion that selling essentially the same car under the Chevrolet, Pontiac, Oldsmobile, Buick and Cadillac moniker was really not that profitable. At one point, these were all separate, independent car companies. Eventually, Pontiac and Oldsmobile went away - as have Plymouth and Mercury.
I remember way WAY back in the day, there was a really great suite of utilities for DOS called PC Tools (not to be confused by a later product with the same name from a different company). Its main and IMO, good but inferior competitor was Norton Utilities. Sadly, Symantec bought (and ruined!

) them both and then killed PC Tools.
Since both Avira and SUPERAntiSpyware are marketed as antimalware solutions, I don't see them both remaining as separate products. Whether that is good for consumers or not, time will tell. But frankly, if they kill off SAS, I don't think many will miss it, "IF" its demise is even noticed!
So we'll have to see what benefits, IF ANY, of this partnership are offered to Free-version users.
As far as the pro vs free versions, I would not expect the free version to ever offer real-time protection or auto-updates. Those are features typically reserved for the paid versions of products. We see that with Malwarebytes and CCleaner, for example. The other typical benefit with paid versions is some form of company provided tech support.