Yes, "quickly" is obviously industry-dependent. If they were fabricating something extremely easy to manufacture, "quickly" might mean months-to-a-year. Fabricating something very complicated like memory "quickly" might mean years.
That said, even though we might have to wait years for new supply to hit there market, we probably don't have to wait years to see signals of that. We will likely know that manufacturers are starting to build new supply long before we see the chips hit the market.
In the current environment unless people start decommissioning datacenters en masse supply will be locked up till the early 2030s IMO.
Even if you started a new fab today, it's 5 years till it comes online. The great hope here is that China's DDR5 yields represent a high reject rate of an enormous amount of new capacity that they'll dump into the market to get a sovereign capability in that area.
Some supply and demand curves move in days, some in months, some on years.