Bigger question might be, is the team big enough that they can afford to do this in house, in terms of the number of person-hours needed to make this happen. Forza says 30 people and 13000 hours. 13000 hours is 6 people for an entire year working on nothing else. Can PD afford to set aside a huge chunk of their entire track modeling team for an entire year? Monetarily yes of course, but how will the other tracks get done? They can't release or create zero tracks for a whole year...or can they? They have for 6 months so far, not counting minor alterations to Monza and Brands Hatch.
The upside to a small, tightly knit team is tighter quality control, better work atmosphere etc. The downside can be slower response times to changing market conditions, slower to produce new product and update old product etc. I have real doubts they can pull this off without bringing people on board to help out, if not permanently, then temporarily, perhaps with some contracting out.