Lightroom "Classic" won't go away for a long, long time. Or if it does, it will be because CC will merge with it. Too many people take too many pictures to be able to sync them all in the cloud. Perhaps a solution that allows primary local storage and selected syncing will work.
As for the Photoshop/Lightroom prediction, I don't think so. They are fundamentally different programs. LR is a parametric editor and not a pixel editor. It completely lacks the ability to do many of the things you can do in Photoshop and I don't see any movement to change that.
I did say that Lightroom classic would only go away after Lightroom CC had all its features and gave a choice of online or local storage. If you look at what Apple did, with FCP and the iWorks suite, they needed to rebuild these product to make them suitable for a cloud based future (or that's what they said) but they couldn't initially port all of the old features over to the new products, with disastrous consequences for the sales of FCP. Adobe have taken a different approach and running the old product alongside the new, for now.
I am assuming that LRCC will catch up, and it doesn't make much sense to sell two identical programs. And I also suspect Adobe will develop new LRCC features that people will want, which will not be added to Classic because its older design won't allow them to be easily added, encouraging a move to the newer product.
Two aspects about Photoshop. The first is that it seems to be getting used less and less by the majority of photographers as LR has added features. Nothing scientific in this assessment, but over the last couple of years I have picked up on more and more photographers saying they rarely go into photoshop now a days, or they don't use it at all. One of the complaints about the subscription model, from some, has been paying for PS when they only use LR.
The second point is about photographers getting a better deal than other Adobe customers. If I was an amateur film maker I would need to pay the full one app sub for Premiere Pro, so why should photographers get a special deal. I suspect its because amateur and professional photographers make up such a large customer base, but it still comes across as an odd pricing structure, and may be considered unfair by other Adobe customers.
But If you look at the current number of photographer plan users, I wonder how many would be happy enough with an enhanced LR only, and how many would cough up the extra to pay the normal single Adobe App price to get PS (probably bundled with LR), and how many would stop using Adobe all together because of it.
My guess is that most would carry on with an LR only sub, a small number would accept doubling their sub to get PS and LR (still a better deal than other Adobe users get), and a tiny number would leave Adobe products behind (but where would they go, Affinity Photo?). Overall increasing Adobe income, as at least some of us would be paying more than we are now.
I just can't see this special half price deal for photographers lasting, and that the people who still feel the need for PS, will just have to pay the extra to get it. Many of the "must have" and professional PS users are probably already on the all apps subscription, so I suspect, in terms of Adobe customers a tiny number are in the must have LR and PS category, and the majority will probably pay the extra.
That's my reasoning anyway, and as I don't use LR, I am anticipating the day coming when I will need to pay the full £20 a month for PS, rather than the £10 a month I do now, or I may become one of the small minority, who at that stage, might move to Affinity Photo.
Cheers,
Graham