This is incredibly sad news. I have been a regular reader of IMDb message boards for over 15 years now. It's the last actual forum that I still visit. There's so much valuable information stored on those boards, it's a tragedy to see it get deleted. Sure the most popular movie threads might be filled with toxic flamewars, but the long tail of more obscure movies has reasonable discussion and human recommendations of…
The value of attaching discussion to a movie database is unmatched by any alternative.
Take for example the old obscure film Stalker (1979). We see discussions 4 pages long about the meaning of the dog in the film. Or this one, "Other 'visually beautiful' films?", and people respond with suggestions. This information will be lost, and the opportunity to create similar threads in a sensible place in context with the movie, also lost.