I believe this is what being refered:
AV出演被害防止・救済法 - Wikipedia
(Google Translate works fairly well for this type of text, for anyone interested)
In short, the relevant points are:
- Individual paper contracts are mandatory for every and each recording.
- At least one month must pass from signing the contract to the recording.
- At least four months must pass from the end of the recording to the work release.
- Models have the right to see the work before its release.
- Regardless of the contract contents, models may refuse any sexual action at any time. And even if they agree to an action during the recording they may still withdraw from the contract with no penalties within one year from the work release.
While it definitely create waves at the porn industry in Japan including recordings cancellations and such, the law was introduced in 2022 June, already more than a year ago, so I find it hard to think that current releases are being delayed because of it.
Also, the studios are not even allowed to announce the new work in the 4 months between recording and release, so if they are able to publish the preview pictures and trailers, legally they are definitely able to release the work itself.
If anything, the model could be in doubt about the release (they do have the right to stop it after all) and the producer could be trying to settle things nicely and create a good relation if they think the model has long-term potential.
Other than that I can only imagine producers' own marketing and financial reasons for the delay.