There's definitely a business sense to bringing out a Switch 2 sooner rather than later. Especially with the scalability of software development and the fact that all companies actually strive to maintain profit and revenue at their highest levels, as opposed to experience years of continual decline. People mistake what has come before in terms of console cycles as some fixed intentional design versus a product of many technical limitations relating to hardware progress and the ability to support hardware with relevant software.
Even historically its worth noting that Sony shipped its highest number of PS1s (highest single year shipment of any sony platform) during the same year that the PS2 launched. Either way it should be expected that Switch will not resemble past console generations. It'll have an active life longer than any past Nintendo system.