Kind of….here is what I would do in more detail:
The day after the race I would do a 1h recovery ride in mid Zone 1
Second day after the race I would take a day off.
3rd day an easy swim and a 45 easy ride.
4th day a foundation ride of about 75min
leading into the weekend, I would do another swim, if I feel good a first easy run and on Sunday a 3-4 hour easy ride.
The second week after the 70.3, I would start the IM plan – for sure the swim and bike part of it. As for the run I would try to stay flexible. Maybe you want to slowly introduce some running and running intensity.
You could either start in week 7 as you said, but you could also start in week 4 and remove weeks later in the plan. It depends a bit on where you have the most room for improvement.
What’s maybe even more important is your nutrition, hydration, stretching and foam rolling after your 70.3. Get your sleep in, recovery hard.
Just my 2 cents.