If they said yes to price cut maybe it will negatively impact its current sales?

As if an interview is the place to announce such things anyway...

outright admitting that they arent working on new hardware is a bad sign. it takes years to develop a console, and the PS5 and next Xbox could very well launch next year. if that happens, game devs arent going to care about the bottom line, the Switch is going to be left in the dust.

Usually Nintendo moves on to R&D for the next console once the current/new console releases. Of course, Nintendo is not gonna disclose anything at this time. Even then, they probably do not want to cause a stir within the industry while the Switch is on a tear and just about to hit its Edit:second birthday.

Well they probably are already considering a price cut for late 2019 (unless they make a revision that starts at $250, then there will be no price cut, maybe at most some more bundles), but it serves them nothing to say that there will be one now.

You’re right. 

Outright admitting they would be working on new hardware would be bad, as then everybody would wait for the new hardware and not buy the current one anymore. Especially since Nintendo consoles are known for several revisions, and thus a successor might have been misinterpreted as a Switch upgrade to come out soon.

Both Microsoft and Sony admitted, but also basically said not before 2020. So at the time they did, that was still 3 years in the future, with the One X not even being released yet. That would have been too long of a wait and thus didn't impact sales

He seems to blurt out a lot of fishy and mildly alarming comments unprovoked. I think he is a bit green in the PR department and could use some minor coaching. Still, of course they aren't considering it at this time. They wouldn't dare reveal any price cuts before they were official and there are Switch revisions first before there will be a successor. Switch could go quite far before a successor would need to be considered. This doesn't mean they are not looking into tech advancements and possibilities for future decisions.

I mean hardly they would said we planning price cut even if they planning one in near future.
Talking about successor, they said that they want Switch to have longer life span than usual 5-6 years, and successor will probably be again Switch (2), so they probably working on Switch revision/s currently instead of successor.