"Massive fight" doesn't mean Islam ducked. It just means Islam's primary concern isn't selling PPVs.
Do I personally wish we had seen Islam vs Topuria? Absolutely. That would be one of the biggest superfights we've seen in the UFC. But that doesn't mean Islam ducked Topuria.
At the end of the day, Islam has to beat JDM. If Islam loses to JDM, then the "Islam ducked Topuria" chants will grow louder than ever. If he beats JDM and makes it look easy, then those chants will quiet down. This story isn't over, but I don't think Islam ducked Topuria, regardless.