You've misunderstood my post: I wasn't claiming Switch is definitely losing momentum, but rather the Wall Street Journal report states that's the reasoning behind this supposed hardware redesign. See this USGamer article for a clearer indication of what Wall Street Journal say in their original report, which is behind a paywall.
If you read my post properly, you'll see I pointed out that a hardware refresh was only a matter time. I speculate that if Switch has lost momentum, that's likely down to this year's software line-up more than it is any hardware issue. I point out that Nintendo's major 2019 titles are yet to launch, and, importantly, that I think we should wait until Nintendo's second quarter results later this month before stating whether or not the system has lost momentum.
I understanded you, but they are wrong, for instance "While not failing, the Switch is certainly not selling as much as in its first year when the Switch first became available in March 2017", is clearly wrong, Switch until now was selling very similar compared to last in same time period, and like you wrote this Holiday season will destroy last years.