Increasing use of ferrite cores?
No, no "proof." All I can offer is my admittedly questionable recollections of buying, installing and using other new electronics. I don't recall any device that came with "Do-It-Yourself" add-on ferrite cores before this Samsung plasma television. In fact, I mentioned (when starting this thread that I recalled installing one earlier, but I since realized that was something else entirely. It looked the same, but was a weight that clamped onto the kitchen sink's sprayer hose, to help the hose retract properly after each use.
So, I checked our two other televisions (both ready for disposal/recycling): neither has ferrite beads on the power cord. Neither was equipped with ferrite for our cable input line, or it would still be there. Looking further, none of our audio components have ferrite lumps (RFI protection) on their power supplies o signal-carrying lines either, despite the congested jumble of speaker wires and wires transferring signal back and forth between my receiver, CD player, DVD recorder/player, television or my (long unused) Teac tape deck.
The only visible use of ferrite RFI protection I found in our home are integrated (inseparable) ferrite beads on the power supply cords that came with our three Dell laptop computers.