Only the new platform can be used for delivering online. Only the legacy platform can be used to export to DVD, Blu-ray, and USB.
If you need to deliver both online and a legacy format to a client for a new project, you should upload to the new platform first, send the Digital Delivery, make sure there are no issues reported by the client, then upload the videos to the legacy platform and create the collection there for legacy format exporting. Since you will be uploading to both platforms, uploading to the legacy platform will not count against your quota.
We understand uploading to both platforms is far from ideal. However, it was our only option to continue offering access to the legacy export feature and gives those members that are still using this feature until the end of 2020 instead of shutting it down in January, 2020. Only a small percentage of our members are still exporting to legacy formats so the majority of our members are not impacted by this need to upload to both platforms. Given the reasons why we could not add the legacy format to the new platform (explained in our detailed write-up), it was either upload to both platforms or have no solution at all for legacy exporting. To help our members, we chose the latter even though there is a considerable cost for us to maintain the legacy platform.