I never read those magazines and I can't say I'm an expert on dungeon map styles, but it's the hatching done in the dungeon walls that Dyson is known for (e.g., https://dysonlogos.blog/2011/09/03/dungeon-doodles-a-crossha...).

It looks like the person that made this program started playing around with the idea May 9 (https://twitter.com/probabletrain/status/1259172635776294912) a day after Dyson started tweeting about his program (https://twitter.com/DysonLogos/status/1258797586464542723).

I think Dyson's program is just a Photoshop extension and Dungeon Scrawl looks way more powerful, but it's worth pointing out the very similar timelines and styles.

Here's someone playing with the concept even earlier though. It did the rounds on reddit at the time, so I'd assumed it was the inspiration.

https://twitter.com/watawatabou/status/1197194111171940352

(in aother tweet, @watawatabou attributes the style to Dyson, though the idea of doing it programatically).

Dungeonscrawl is definitely inspired by Dyson.

Here are some tweets by the maker:

https://twitter.com/probabletrain/status/1259172635776294912... https://twitter.com/probabletrain/status/1258821040937013248...

That cross-hatching-in-the-walls thing is fairly distinct, and I saw it immediately on Dyson's blog but not on a quick survey of old Dragon/Dungeon maps. That said, Dyson is clearly going for that aesthetic mostly, so it could be convergent evolution, and I'm hardly up to date on current styles for maps in other places.

Just taking a look at Dungeon Magazine on archive.org and it seems that crosshatching in walls is pretty common, at least in the early editions.

https://archive.org/details/Dungeon_Magazine_002/page/n25/mo...

https://archive.org/details/Dungeon_Magazine_002/page/n45/mo...

https://archive.org/details/Dungeon_Magazine_002/page/n51/mo...

https://archive.org/details/Dungeon_Magazine_003/page/n31/mo...

https://archive.org/details/Dungeon_Magazine_003/page/n41/mo...

The style really reminds me of old Chaosium maps, from the 1980s.