No official announcement as of yet, because the price was increased in a somewhat sneaky manner. So far, only lord packs for Warhammer II seem to have been affected, but there's always the possibility that more might follow in the future. The fact that the last lord pack for Warhammer II is going to be released in a few weeks (early December) is almost certainly not a coincidence. The difference may appear small, but relatively speaking, it's quite considerable, judging from the cost of the average DLC. Nowadays, lord packs cost more than the old faction DLCs.

Κeep also in mind that this is the second price hike in the time-span of a single year. In August 2019, there were similar price increases in several DLCs and not just Warhammer II lord packs. For instance, it also affected DLCs for Rome II, as well as all the blood packs. The latter is especially ironic, given that their price is supposed to be purely symbolic and often justified, under the pretext of age-restrictions. Looks like the price of symbolism and EULA has become more expensive recently... In my opinion, this is not a very example of pro-consumer business practices. Even if the price hike was the result of inflation or currency patterns, it would more respectable of Creative Assembly to publicly admit it, instead of hoping that customers will simply ignore the issue. From a cynical perspective, however, their policy is perfectly reasonable, as, in the social media, memes gain thousands of karma points, but the thread about the price increase barely reaced 200 positive votes.