Probably No Such Resistances, but Hard to Be Sure
The specific beats the general and a stat block should give all relevant abilities, immunities, etc. The NPC stat block for Drow, for example, includes and explains the "Fey Ancestry" trait, even though that is something which per the Player's Handbook is an attribute of all elves. The style approach for creature statistics never seems to be to just give general rules at the beginning of a section for a type of creature and then leave them out of stat blocks. Instead of just telling us somewhere, for example, that all dragons speak draconic, each and every stat block for each and every dragon lists it. Perhaps a more extreme example is repeatedly explaining what "Magic Resistance" means for every creature that has it. Generally the idea seems to be to minimize the necessary knowledge of rules beyond the basic rules.
It is important to note, however, that in this case these are essentially statistics for a vehicle, and are more limited than a standard creature stat block (notice the lack of ability scores, even though it presumably at least has something like a Strength score). We have limited comparable things in game to compare it to.
Nevertheless, given that it states specific immunities, it seems much more in keeping with WotC's style to list off resistances to all other types of damage (one by one) if applicable. They tend to be as explicit about damage resistances and immunities as possible. But there are places where they give less information than they could on other sorts of things relating to stat blocks, such as making no mention of being a possible mount or how that would work as such in the stat blocks for the riding horse and similar creatures.
On balance, I would err heavily on the side of saying it does not have resistances to all damage. The universal damage resistance seems particularly unlikely, given that the manual merely says that "most magic items" which aren't spells and potions have magic resistance, so there are clearly unspecified exceptions. It also seems like a very byzantine rules design choice to require knowledge of this rarely invoked general attribute of magical items in this specific context where damage is clearly anticipated.
