Hi Jakub Groos
At the moment, there has been no official statement from Mojang or Microsoft confirming whether this behavior is an intended limitation or a bug. However, multiple players have recently reported that Minecraft Dungeons II Deluxe Edition content is only available to the profile that purchased/redeemed it on Nintendo Switch 2, while other profiles on the same console can access only the base game and are prompted to upgrade separately. Similar reports have also been mentioned for PS5.
Because there is no official confirmation yet, it is not possible to say whether the future DLC included with the Deluxe Edition will be shared with other profiles or remain restricted to the purchasing account. Likewise, no fix or timetable has been announced.
For now, I recommend monitoring official Minecraft/Mojang announcements and reporting the issue through Minecraft Support so the team can confirm whether this is a bug and provide updates if a fix is planned