Courts set time limits, Tesla requests extensions, repeat. Tesla is delaying on purpose; it's very likely they knew at the beginning that all batteries were affected and all would be capped eventually unless they designed a new battery that doesn't have the defect any more and they hired one of the most expensive and high profile legal teams in the world to represent them for Batterygate, which is unusual for Tesla to put it mildly.
Not having any plan to address batterygate at the outset would explain their lack of a response and the anti-owner attitude they adopted from the beginning, as well new 350v 89kwh "85" replacement in testing now. If it gets eventually capped 10% it will still hold 265 miles of range, and that doesn't seem accidental to me. Nor does the 2020 warranty exclusion term changes that explicitly say they will software limit range as much as 30% even on brand new cars, along with the reduction in warranty coverage to 150k miles. Batterygate may not have a real fix and could just be an inherent limitation in Tesla (or all) car battery technology. Or at last that's how Tesla presents it with their responses, and since they don't talk we can only assume based on their actions that lead to these conclusions.
I think they were blindsided by all those fires last year, but came up with a quick fix they thought would be invisible. When they realized their mistake it was too late, and now they are scrambling to come up with ways to address the problem before legal responsibilities force their hand. Thus, delay delay delay and all the while they increase their warranty coverage reserves. If they weren't delaying, and had no actual fix, everybody would be ordered to get new batteries, and Tesla would have the same problem again in a few years when the new batteries started showing the same flaws.