It may be possible to create a fake certificate for a fake ROA.
However, to do that requires a lot of steps to go right.
First, the RSA private key needs to be derived from the public key.
The quantum computer physics exists to do it.
However, the known technology is massively behind and may never materialize.
OTOH, it is a wide open field and someone may find a way to create enough
qubits and entangle them all and keep them stable long enough to
perform the calculation tomorrow.
People have been trying for several years, so this is extremely unlikely.
Second, relying parties need to be convinced/tricked into downloading
the fake certificates. Since each certificate contains the publication points
of its child certificates, the certs are chained together.
The route to a publication point needs to be hacked to cause relying parties
to access the fake publication point.
A point was made that encrypted data can be captured and stored and then
be decrypted later once the technology becomes available. This possibility
is not useful for creating fake ROA certs.
Therefore quantum resistant certificates will not be needed in advance of
the development of quantum certificate crackers.