Sona/Taric and Funneling Should Stay, Riot Should Pump the Brakes
A meta shift that changes the way a game is played is more valuable than a shift that changes which champion you're facing, and so these strategies shouldn't be nerfed out of the game.
Strategical shifts are the 18 wheelers of driving the meta. The changes they bring are powerful and far reaching, often innovative. Lane swapping led to new early ward spots; some of my favorite moments were watching teams invade deep into each other's jungles to try to spot out which champions were going where. Double jungle came about because some top champions just couldn't contest cs early on against two people, so it was more valuable to help the jungler clear a few camps. This in turn affected the jungle meta, champs and routes both changed. Mid laners had to adapt to new gank timings. Eventually RIOT stepped in and fixed the issue, but evidently so much changed because of just one strategical shift.
Click this link to see other examples of "revolutionary meta changes" and what can happen if a meta is allowed to evolve mostly organically: https://liquipedia.net/starcraft/Metagame
Just due to the sheer rarity of new strategies they're more valuable than shifting tier lists. There's a new tier list every couple of weeks and it changes what we play, but strategical shifts happen much less often and change how we play. It's a fresh challenge, and that helps keep players playing.
Sona/Taric strat might need nerfs at some point, but don't nerf the strategy out of the game. Rumor is funneling can beat the late game strategy, so as long as it has a viable counter and isn't pushing every other strategy out of the game it's ok. If it is pushing every strategy other than counters out of the game it'll need nerfs to bring it in line as an option, as opposed to the option.
Challenging pro players and analysts to think outside the box is what a vibrant meta should do, and shifting strategies do it best. New strategies are often required in response to strategical shifts, thus it forces players to expand their options through experimentation. As the existence of Sona/Taric shows, the meta isn't solved and there can certainly be a strategical counter to Sona/Taric that hasn't been found yet. Allowing players to launch a response to dominant strategies before stepping in with a nerf hammer is part of good balance. It's fun to use new strategies, it's fun to find new strategies, and it's fucking amazing when you're the one who finds the new meta strat.
TLDR: I hope we see pros drive the meta in response to a new strategy, because that's more interesting than watching new strategies get the nerf bat.
