There will be a lot on the market. To varying degrees, these consoles do fight for the same markets. However, I think the greatest threat to new consoles are the current gen of consoles. MS and Sony may well cannibalize their first few years of sales if they plan on continuing to support, deeply discount, or even offer new skus of these old systems. If the grand business scheme is looking for big numbers and immediate gratification, they will probably find it here rather than in the new consoles, but I think that will harm the companies going forward if it slows adoption.
Publisher losses/closures
I don't think this is anything to cry fire about. A lot of publishers have become over-bloated behemoths and a reckoning was due. It was going to happen sooner or later, and the area between generations is as good a place as any for it to occur. I think there are too many factors to claim it is a sickness of the whole industry.
Major blockbusters underperforming
I'm not certain of the veracity of your claims about a lot of those games, but there certainly is a lot of fatigue for a lot of gamers in relation to the seemingly endless, sequel-driven business model. Should that continue, then this lack of innovation may well bore people to the degree that they stop buying said games, but that doesn't mean they won't keep gaming. New titles like Tomb Raider failing to meet expectations are a symptom of unrealistic expectations for an IP reboot. I don't think there is much here.
Major competition from Tablet/mobile gaming/resurgence of PC gaming
I'm going to contest your suggestions here. If you're talking about a crash in handheld gaming, then I think tablet and mobile phones are a serious competitor, but the people looking to buy an Xbox Next or PS4 aren't going to be satisfied with what is on offer on mobile platforms. Not the same market. As far as a "resurgence of PC gaming," I think that has yet to be seen. Have a substantial number of people picked up PCs over the last few years? Certainly, but is that because consoles are so long in the tooth as to be easily overcome by affordable hardware, or because PC gaming is being viewed as a better alternative? I'm not convinced its the latter for most consumers. PCs that overcome what you see in the next consoles, at least for the next few years, are still going to be very expensive, and offering your general consumer a choice between something that costs $500~ and works out of the box or $1000+, requires assembly, and gets marginal improvements over consoles seems like a tough proposition. There are certainly people who have been "converted" from consoles to PCs, but I doubt that populations is very large.
Even if though both your contentions are true, mobile platforms and PCs are entirely capable of playing the full spectrum of video games. Their existence may well buoy the industry if enough people have them. Ergo, no crash, just a movement to different platforms.
So, my ultimate conclusion is that your smoke is questionable at best, and there certainly isn't any fire; not yet. There is plenty to be said about market saturation and many feeling like this generation is "good enough," but I think the rest of your extrapolation goes too far.