I just got a renewal invoice for my LastPass/Xmarks Combo Premium subscription, so it appears to still exist as a combo (at least for those of us who already have it, I don't know if they've removed the option to buy a new combo). I was charged $32 this year, compared to $20 last year, so it looks like they just included the Lastpass premium price increase into the combo.
Last time I inquired in a support ticket they told me that they plan to maintain the lastpass extension but currently have no future plans to add new features. The fact that there is a beta extension for firefox that is based on webextension and should therefore be 57+ compatible gives me hope that they aren't just abandoning it yet. I presume, on the other hand, there will never be an Edge extension or new features.
In truth, it works pretty well in firefox, so I'm okay continuing to pay for now. I prefer it to firefox's native sync in that you can have different profiles so you can customize for different computers/browsers. Other than that I suppose the native firefox sync is good enough that it could probably replace xmarks in most respects. I don't use the cross-browser capability because firefox is the only browser I know of that supports bookmark tags (one of the several reasons I'm still using firefox) and I don't trust that syncing on other browsers won't muck up my tags. But it is nice to be able to go the the xmarks website to search for a bookmarks if I'm on a different platform. I'd love to see an extended chrome extension with tag support (since Google will never add this feature) but that would require a level of development that LastPass is clearly not interested in doing at this point.