At this time, I'm afraid we don't have an ETA for the 2.0 version of the importer. However, you can still do the import via 1.5. That would be our recommended approach until any necessary 2.0 importer has been released.
What would be the difference specifically? We have millions of photos embedded into millions of posts from photopost over decades that also need importing. This is not a small, simple project unfortunately, so we need to understand exactly what this means, before making any decisions. Thank you.
In terms of the import, the XF2 importers are in beta as is, so the XF1 importers may be considered more stable currently. If it's a large forum, then you may want to use something like the big board importer and AFAIK, that's only for XF1 anyway. (Plus the gallery import, which is only for XF1 as is.) Beyond that, I don't know if you need redirects for the embeds. If you maintain IDs, you may be able to do that...
Unfortunately, we have millions of gallery images embedded in millions of posts that need to be retained. Due to Slavik's comments in the next post, we are not confident that the import would be a success and cannot possibly double check millions of pages to be sure there wasn't anything lost in the shuffle. Please let me know if you'd like to take this offsite in a phone call or emails with my team. Thank you.
"XF1 gallery import is, not ideal, XF1 didnt support Albums within categories, so imported items could look extremely out of place
This will change in XF2 media gallery, but those importers are still in alpha stage, and certainly not reliable enough to be used on a production import
If you go via XF1, you may need to spend considerable time manually re-assigning albums to categories once the upgrade to Xf2 is done"
Unfortunately, I don't really have another recommendation at this time. XFMG 2.0 importers are on our list, but they are a significant undertaking. We don't have any ETA for them being released. Our only current recommendation is to use the 1.5 imports. If they don't fit your needs, then the only other option I see is custom development.