The Australia/France bilateral permits a total of 3.0 units of capacity between Australia and France itself (the same bilateral also covers New Caledonia and French Polynesia as Routes 2 and 3). There is an aircraft substitution formula for interpreting the 3.0 units of capacity which, as someone already mentioned, is seat-based. There is also provision for excess capacity of up to 0.25 units of capacity (i.e. a total of 3.25) if the application of the formula "will result in the total capacity entitlements for the designated airlines of Australia being exceeded." The bilateral treaty and the register of available capacity (which should always be read together with the relevant air services agreement / MoU) are available in the International Aviation section of http://www.infrastructure.gov.au
A Qantas B789, at 236 seats, equals 0.5 units of capacity, therefore a total of 6x weekly services with that type would be permissible under the bilateral.
B744s VH-OJM & -OEB, which have 353 seats and are equal to 0.8 units of capacity, 4x weekly services would be possible. All of the remaining B744s (with 364 seats) are equal to 0.9 units of capacity and would therefore only permit 3x weekly services. With an aircraft the likes of the B789 in the fleet, it makes absolutely no sense to go after CDG with the B744s.
However, I understand that Australia and France negotiated what's known as extra-bilateral rights last year, which reportedly would allow QF to operate daily with the B789 (in fact, from memory, I believe QF made some kind of announcement to that effect, including naming the B789 as the relevant aircraft). Now, we know that all 8 of the first batch of B789s are spoken for, so presumably CDG is intended to be among the routes that QF would announce with the arrival of numbers 9 and onwards.