Please note, and I said it multiple times knowing fanboys will fanboy, none of my comments had anything to do with the actual watches, engineering, or finishing of the final product and I distinguished the people making the watches from the brand as it's own entity. All my comments are around the brand which I think are considerations when spending quite a bit on a watch and wondering about resale expectations.
As a fanboy, I'd suggest that you're letting your letting your enthusiasm make excuses for the brand. The idea they have zero digital presence for lack of need or that offline efforts are a substitute for online are a stretch. For the first, I'm not even talking about digital marketing and going all hype train with celebrities and super heroes, I'm just talking about table stakes, a home on the internet to say we exist, we make a thing, and even if all the things are already sold out, we're proud of the thing that we accomplished and we put a page up to share it with the world and it becomes part of a lineage of great accomplishments. Why shouldn't that be online? I've worked with some great brands that don't exist today because they didn't think they needed to do the things that had become just normal for their customers and their competitors.
As for offline, well, if they are doing all this offline branding, why not do online branding too? Take the watch the OP is considering, he tried it on in person and now he's thinking about making a purchase decision, mulling over spending >$100k, and Montblanc doesn't even have a web page about it for him to contemplate? Offline, online, they are not mutually exclusive not substitutes, if they are so serious about the brand and their customers, why not do both? Consider the reverse:
1. Why shouldn't Montblanc market online?
2. Why should Montblanc do offline branding but not online brand marketing?