I'd say PS waits until mid gen to try a discless model, if their going to. The real point is for people who need to save money. $399 and $499 isn't for those consumers. Typical year 1 and 2 buyers don't have that problem, and a discless console would be seen as a luxury, not a necessity.
Launch a $299 1080p/60 SKU, and a $499 4k/60 SKU. After 3 years, when the 1080p model is slimmed and dropped to $199, offer a third SKU at 1080p, but with no disc drive or mass storage drive for $99. Let the customer buy an external storage drive of whatever size they want for $50-$100. PS can offer a few sizes for convenience if they like.
At the same time, when the 4k/60 model is slimmed and dropped to $399, they could, also do the same thing an add a 4th SKU at 4k, but with no disc drive or mass storage drive for $299. Let the customer buy an external storage drive of whatever size they want for $50-$100. Digital should require much more storage space anyway.
This would give PS a full line up from top to bottom mid gen. $99, $199, $299, $399. While they could just launch all 4 SKU's right off the bat, $199, $299, $399, $499, I'd think it may be too confusing for some customers and may put people off, so it might be better to wait until mid gen once momentum has been built up.
There is also the possibility of keeping the disc drive and dropping the mass storage instead. Many casuals would need to learn one way or another, that some consoles don't have disc drives or all don't have mass storage. Design every SKU to retail at a $99 price point without mass storage, and let the customer buy an external of their choosing, instead of paying $50 extra for the console and it's absolute minimal storage limitations. Consoles don't like to sell for $49 prices anyway.
Just some suggestions if a lower price point is that necessary for marketing and sales next gen.
