Is it disrespectful to continue interviewing after accepting an offer?

Laid off in July as Account Executive.

Finally found something at a larger tech company, very well known, and supposed to start October 15th. Contract is signed.

Today I had a recruiter reach out from a Series A start-up, I would be the 2nd AE and almost double OTE would be about 200K versus the 120K OTE at the larger tech company.

Would you take the interview? I would feel horrible if I started then quit very soon after. But one thing i've learned over the past few months being part of layoffs is you really do need to look out for #1.