From what was said in the SBS, Oda clearly said that Zoro wasn’t here because he was the VC.
And then he talked about Beto strength being only second to Law
Yes, I agree with that; Zoro wasn't there because he was the vice-captain.
The important detail here is that Oda didn't simply state it directly, with his own words, that Bepo was chosen because he is the strongest among the No.2s; Oda went out of his way to make it clear that Bepo was chosen because the other No.2s (Penguin and Shachi) acknowledge with their own words that Bepo is in fact stronger.
So Bepo's case is different in comparison to Zoro's case; Neither Sanji nor Zoro would recognize that the other one is stronger, regardless of who is in fact the stronger one.
Among the No.2s in Heart Pirates there's no rivalry between two who disagree about who is the stronger;
Among the No.2s in the Straw Hat Pirates, on the other hand, there's clearly a rivalry between Sanji and Zoro, with each one believing to be stronger than the other.
So Bepo's situation is not comparable with Zoro's reason for being chosen to be in the colour spread, which hasn't been clarified by Oda, so it's open to our imagination; It may be for one reason or another, such as that it was because of Zoro's popularity, or just because some of Zoro's confirmed opponents would be there anyway, so Sanji would look out of place in it.
But there's no direct confirmation from Oda as to what exactly was really the reason.
Keep in mind that the question in the SBS was about Bepo, and not about Zoro; Zoro's name was just mentioned there because Oda wanted to use the opportunity to clarify that Zoro is in fact not the vice-captain. But Oda was really literally just referring to Bepo in the rest of the answer.