I can't see the need for 3 urethane balls at once. There can't possibly be enough differences in the core/covers to justify it. Also, I've been told that both Ebi Stingers and Brunswick Igniters are discontinued which is odd mid-season to dump good selling mid price balls. The speculation is that they are having trouble getting blue dye and are trying to save it for higher end pieces. This kind of makes a red pearl and black solid ideal replacements.
Back when the original Fab Hammers came out (also in Black, Red Pearl, and Purple), there were enough differences in just the covers alone to justify it. If I remember correctly, in order of strongest cover to weakest cover, went Burgundy, Blue, Purple, Black, Red, Red Pearl, Blue Pearl, then finally, Pink.
Now granted, those were released over the span of 10 years, but there was a decent difference between them to justify all of them. Now, if they are looking to discontinue the current Purple Pearl Urethane, bowlers will be clamoring for another pearl urethane to replace it, which is where Red Pearl comes in. So there is justification for that.
Black and Purple? Black would just be a refit/upgrade of the last Black urethane Hopkinsville pour, so that's a straight 1:1 there. Purple solid is where there will be a difference. The Faball pour of the Purple was more suited for oil than the Black, but a softer cover than Blue or Burgundy, so if the trend holds, it will be a harder hooking ball than the black, but possibly not as versatile as Red Pearl (I'm basing that versatility off of Purple Pearl, which Red Pearl should replace in terms of performance).
So the justifications are there; what remains to be seen is how they will work (read: need to see these in a demo).
BL.