Use opto isolator on the PWM pin of the IR2184
Note that this answer was made prior to the OP showing a picture of the magnetic coupler proposed (note this is not an opto coupler despite the question explicitly stating "opto-isolated" in the title).
PWM operating frequency is going to kick you in the teeth unless you are running sub 10 kHz or you can find a really good opto-isolator that has fast rise and falls times.
A hand waving typical rise and fall time for an opto might be about 5 us and this will be into a quite low load resistance of about 100 ohm. Into 1 kohm it could rise to 20 us or more. Now, if it takes 20 us to deliver a PWM "edge" then you don't want to be switching too often or the rise/fall time inefficiences will be warming things up. So maybe 20 us represents 5% of the period of your PWM.
If you work that out you'd choose a PWM frequency of 2.5 kHz because 2.5 kHz has a period of 400 us and 5% of that is 20 us. But it's a little worse because there are two edges to consider in each PWM cycle so, you'd choose 1.25 kHz as your PWM frequency.
Regards the ADuM3223 - it is a good device and has a rise/fall time less than 100 ns!