Whole camera work stagnation happened after one main thing.

It is the private agreement between Samsung and Sony, Sony agreed to transfer lot of their small sensor design knowledge and tech, as well as providing sensors for big discounts compared to open market. In return Samsung suddenly closed all large sensors design teams and manufacturing and moved out from consumer cameras market where Sony did not want such strong competitor. Companies will never admit existence of such agreement publically, as it is punishable crime and will lead to multibillion fines. But insiders confirm this.

With fast rising tensions the breakup of this agreement can happen very soon. It is strong rumors that Samsung secretly reestablished large sensor design teams around 1-1.5 years ago. Samsung also barely requires any Sony technologies now.

As US-China trade war will escalate Samsung will have no other choice but to dump Sony in the attempt to significantly lower sensor costs by using only their own sensors and not financing Sony last profitable division. Samsung also looking at providing sensors to Huawei (who also work on their own ones for safety!) and want to stop the fast growing Chinese industry that can be extreme threat to them.

If such things will happen we can see total disaster of Sony division (that already lost top managers who where assigned to do impossible - save the totally failed smartphone division). As costs of new sensors development, especially complex stacked ones, are rising and Japanese semiconductors factories are lagging more and more behind competition it can be impossible for them to do new competitive sensors, and hence to use mobile income to finance the camera department and developing of large sensors.

In 2-3 years we can see total Sony demise, as well as long time proposing merger of 4 leading Japanese camera brands into one company.

One of the camera industry insiders told that all leading Japanese companies are very worried now, especially considering Samsung moves in near future.

And yes, we can see $999 FF camera from Samsung in less then 2 years with around 40% probability.