All trial versions of Magix product are in some way limited; such limitations are removed when the full version is purchased. My impression is that the full set of ACID loops is available only after purchase.
With reference to the linked page on ProducerPlanet: the three packs are not specifically Acid loops, but rather a Sound FX pack and two Soundpools, so perhaps more intended for Music Maker etc.?
Even if you purchase Soundpools or samples on Producerplanet, like I do, you can tick acid versions. But I have been using Magix sound pools for years in Acid Pro.