WOTC has announced a problem with the collector boosters for Ikoria, which actually benefits the collector booster purchases. Each of the collector boosters was supposed to have a chance of containing a Japanese alternate art card but those got left out. Stores will now get 4 card packs, rather like the FNM promo packs., that contain 3 non-foil alternate art cards and 1 foil version of one of the three cards. If you buy 3 collector boosters, you get 1 random card from the pack. If you buy a full box of Ikoria collector boosters, you get the full pack.
This works out better for the collector, since before you only had a chance of getting a Japanese card, now you will certainly get one, if you purchase at least 3 packs. Unfortunately, these won't be available on the release date. We will keep track of your purchases as WOTC says they should arrive in late May.