There will always be front projection for years and years to come.
The 100" Sony is $20,000. It certainly is a long way from $5,000. It isn't going to be a quick downward spiral to get these sizes to a reasonable price point. I've been doing 98" displays in businesses for over five years now, and their price point is a bit prohibitive, but their size isn't nearly as impressive as some may hope. Especially when reading details from 15+ feet away. In the home, it may be a bit different.
But, those with a basement, with a love of movies, with a love of cinema, will ALWAYS lean towards front projection.
JVC is also out there leading the way as they move their entire new lineup to an all laser system of projectors. They certainly won't be the last.
Over the years we've seen projectors grow from a few hundred lumens calibrated, to well over 1,000 on most projectors. As they continue to get brighter, it will allow smaller screens to do a better job with HDR content, and will allow for great SDR viewing at extremely large sizes for the rooms and homes which can allow for it.
My own basement has standard 8 foot ceilings and I'm running a 161" screen. It's truly a fun cinematic experience that my family always feels is special to watch and enjoy despite us having a 85" display right upstairs in the family room. This screen is nearly four times the size of a 85" TV.
At the end of all of it, a home theater feels different. A good home theater is dark for a reason. It creates a room that is far different than any other room in your home. It's quiet, dark, and peaceful when done right. A theater screen also imparts a far different feel into the room than a LCD display glaring it's light into your eyes.
Yes, I am all about getting a 100" TV, but it certainly won't be a replacement to my front projection setup. For those who enjoy front projection, it won't replace their setup either. With the continued dropping in price of front projection and a cost of entry that can be well under $2,000 for 4K and under $1,000 for 1080p, it's not likely to go away either when you can get a solid 4K image on a 135" screen for your money. Even optimistically, that's not likely to happen with TVs anytime in the next decade, if ever, due to the large physical solid screen size a flat panel LCD would have to deal with, the requirement for professional installation, and the fragile nature of displays of that size.