Short answer: no.
That's from the standpoint that most, including the OP are approaching this question from which is to say "If Nintendo, Microsoft and Sony are competing in the same home console market, will Nintendo dominate that market for the duration of the hardware generation in terms of units sold and revenue generated?"
Again; no.
The flip side that most probably aren't thinking of is a potential future in which Nintendo is the last of these companies to be manufacturing and selling dedicated game consoles as Sony and Microsoft continue to evolve further into services and content based entertainment businesses. Yes, they will all be selling games (or access to games) within a walled environment, but the hardware will likely be less of the focus in the future, whereas Nintendo is most likely to remain a toy manufacturing company.
In such a future, Nintendo may well be the only company selling video game consoles (so 100% of the console market), but not the only company selling games within a walled environment and not the company producing the most revenue from games and related services.







