Hello,
I'm not part of the OsCommerce team, I've just been a user for 17 years and haven't upgraded to the latest version yet.
If I answer you, it is to bring to your attention this: The vast majority of the OsCommerce team is in Ukraine. They endure the war and do what they can depending on the bombardments and power cuts. I saw on the team page that there have been changes, I hope nothing serious has happened to the one that is no longer on the list.
If you have any questions about how OsCommerce V4 works, feel free to ask them on the forum, other users are there to help you based on their knowledge and experience of the software.
For your hosting concerns, I think the OsCommerce team will do the right thing as soon as they can.