You had it, and then you lost it.
You talked about feedback loops that restore a system to equilibrium (which, indeed, are amply demonstrated in everything from physical to biological systems on Earth), then (somehow) assume this isn't one.
As you mention, nature frequently has feedback loops that offset changing conditions. If the "sweet spot" comfort zone of the natural system on earth were anywhere near as desperately sensitive one as it's currently portrayed, then over the 4+ billion year history of life on earth - and the half dozen cataclysmic extinction events that wipe out 3/4+ of the extant species - the climate would have spun off into one of these feedback loops that are so desperately (hopefully?) projected and we'd have a lifeless Venus or a dessicated Mars. We don't, ergo the system is robust, QED.
To your specific point, we even have several historical examples in the ice records of (geologically) sudden 'pulses' in CO2 and temperature to levels comparable or exceeding today.* In every case the system has then returned to an equilibrium....DOZENS of times over the past couple of million years. The feedback loops you talk about are real; the cataclysmic FUD you're talking about negative feedback is, quite evidently, not. I'll post 4 billion years of actual historical record of far more substantial shocks to the climate of this planet, against 15 years of panicky hypochondriac environmentalists finally devising an issue with some purchase in the public mind.
*some might point out that it happens every 120k years so so, and the last one was about 120k years ago. Yet this specific instance, curiously, is deemed to be "caused by" humans? If I stood on a beach, and knew that the tide came in 10 times before, regularly, and now it is rising for an 11th time, what sort of a moron would I be to assume THIS TIME it's because I'm standing there?
The article itself states clearly that they have no idea how long these seeps have in fact been going on - while other seeps have been researched specifically for that and found NO BASIS for believing they're getting worse. So to automagically jump to the conclusion (which the article desperately tries to - "it's hard to prove they're the result of climate change" - as if that was the end goal of all research, right?) suggest at least faulty science, if not downright mendacity.
Want a feedback loop? How about this - the seeps are extremely sensitive to ocean temp and pressure. The article suggests that a warming ocean might(hopefully, again) be the cause. But if the planet is warming, and seas are rising, this is going to put those seeps under deeper water, which is in fact more likely to slow them down. And if they've been bubbling away forever (ie contributing steadily and unaccounted-for levels of methane to the atmosphere), this could be the mechanism that then reverses warming.