Nintendo won't be changing the tickrate. Switch is being touted as a home console you can take on the go and they've put emphasis on the idea of tethering your Switch to your phone as a portable hotspot and using the (very terrible) Switch Online App for communicating with friends. That plus increasing the tickrate will put many more people at risk of disconnecting, as not everywhere has great internet speeds or can afford the high costs of fibre broadband. Nintendo's main target will be the broader casual audience, and they won't want to alienate that to please the minority (which are competitive players). They aren't interested in eSports, as their NintendoVS Twitter says clearly that it's "social competitive gaming", so they'll probably have occasional competitive tournaments to advertise and promote their games like they did at this year's E3. Their online was never going to be worth the asking price as it's all Peer-to-Peer which is far cheaper than dedicated servers and has little impact on Ninty's outgoing costs. Increasing tickrate will fix some issues whilst adding more, more strain on people's internet connections puts higher risks of dropped packets, leading to more lag and spontaneously exploding halfway across the map as the game lumps the packets into the next data transmission.
I won't excuse Nintendo and their shoddy online, because Mario Kart 8 Deluxe is a broken mess online, but Splatoon 2 has been mostly an improvement and step up for me. There have still been laggy matches and players, but not even the best netcode and online will fix that. The tickrate being low is definitely causing some questionable splats where someone kills you in 1 or 2 hits when their weapon has a higher hit to kill requirement, and yes being killed from outside enemy range or behind cover still happens, but mostly the lag has cleared up since 1, which could be being masked by the low ping connection requirement making matches more or less regionals. But looking at the game from only the competitive viewpoint is totally unfair to the thousands of players who spent £50/$50 on this game and lose access to playing it because their connections can no longer handle the demand from a higher tickrate. I honestly don't think Nintendo cares for eSports, and they're only using it to fuel their own means of promoting their games. Besides, LAN play exists now and will be used for local events and tourneys, but the online will still be questionable at times. Just one of those things you'll have to deal with considering Nintendo's complete incompetence at online, hasn't improved in 10 years and that's shocking, but it is what it is. Maybe we can get through to them and slightly improve the tickrate, but it won't magically jump up too high for their fear of alienating their family and children audience.
