Backwards compatibility still likely to come with a later firmware update

[Reasonable]

I can't remember which is which but essentially first PS3s had two chips to support PS2 titles, then later one was yanked to cut costs while the other was left in place with emulation to replace the other chip. This only gave partial support though and even supported titles could have glitches, etc.

For BC to return, unless Sony stick the chips back they would need to drastically improve the emulation. This is possible of course, but I wouldn't hold my breath waiting.