It's interesting; Diamond & Pearl are simultaneously the main entries that are most in need of a remake, yet the entries whose inevitable remake could not instill any less interest. Part of that stems from the vanilla versions being outright awful, a tedious slog with lacklustre animation and music (save for the Champion's theme being, arguably, the best in the entire series) whose best moments came from paying homage to better entries in the series that had the worst native Dex that somehow managed to make its odd decision to limit a significant amount to the post-game portion of the game all the worse by locking off certain Pokémon to those who owned a copy of various Gen III cartridges. Part of it may be due to how much time I spent playing the 4th generation as a whole, the Sinnoh entries in particular: Pokémon Diamond remains the game i've poured the most hours into both collectively and for a single playthrough while Gen IV remains the only time I bought every entry in the usual trio of generational releases, with thousands of hours spread out between experimenting with different teams and playing with friends in tournaments we would host across the summer, keeping tracking of scores across seasons and seeing who would be the best by the end. Given how long i've played each of them, how many fond memories my experience with these games forged, not to mention how much the metagame has changed since then-top tier Pokémon like Electivire and Staraptor were introduced, I don't imagine a remake will ever be able to wash out the bad taste the original games themselves left without a serious overall nor will the multiplayer be able to capture that sense of community and belonging Diamond & Pearl gave.
P.S. Platinum is still garbage. Adding in a few more Pokémon and a new setting with some interesting visuals but continuing the tedious exploration does not a good purchase make...although it does help make it slightly more palatable. Also Heartgold/SoulSilver are weighed down by Gen IV, not enhanced by it.