Can a 30,000 word story qualify as a novel in publication?

No.

The definition and expectations of a novel have changed over time, but in no plane of reality has 30,000 words ever been a novel.

To give you a sense of expectations:

Right now, the average length of a novel on Amazon is between 94,000 words and 96,000 words.

Most major publishers will tell you in their querying guidelines they categorically won’t accept, and will discard unread, any novel manuscript under 80,000 words.

Genres differ, but even formula romance, one of the shortest genres, is expected to be 60,000–70,000 words.

Science fiction and fantasy are routinely 120,000–140,000 words or more; in other words, if your story is sci-fi or fantasy you’re about 100,000 words short. What you have is the setup for a story, not the story.

30,000 words is a reasonable length for a novella or a king short story, but it’s definitely not a novel.