The first is planned obsolescence, the second is not. The first is deliberately trying to limit lifespan in order to prevent someone who paid for the cheaper product from using it for a longer period of time than they paid for even if product quality is sufficient to allow it. The second is cutting costs to the bare minimum, while hoping that the vast majority of the bulbs will last at least as long as claimed, they do not care that some last much longer, they already saved the money on the manufacturing end and if some people get some bonus life that reflects positively on the company. If too many people pay for 1000 hours and only get 500 hours that is a disaster, but if 99% of the people who pay for 1000 hours get between 1000 and say 3000 hours you're doing really well. If a large percentage of people who paid for 1000 hours are getting 10,000 hours then you were too conservative in your cost engineering, or you should talk to marketing about increasing the rated life.
A tangent related to lighting, many HID lamps, particularly mercury vapor and metal halide lamps don't really "burn out" like incandescent. Instead the lumen output gradually depreciates over time until they reach a point referred to as L70, which is 70% of initial rated lumens at which point they are considered worn out. Power consumption remains constant or actually increases with many so the result is the lamps become dimmer and less efficient as they age and will often burn out the ballast in the process. Eventually they will fail completely, occasionally, especially in the case of metal halide, that failure comes in the form of a rupture of the pressurized arc tube. In a few cases it gets even more exciting and the rupture shatters the outer envelope spraying out red hot shards of quartz, an event referred to as a "non-passive" failure. The problem is people see a light that is still lighting up and they say it's still good, it hasn't burned out yet! They may claim the advice of replacing these lamps as planned obsolescence because in their mind the lamps haven't burned out yet, nevermind the fact that they are only producing half or less as much light as they are designed to while consuming the full rated power or more, and the risk of a dangerous failure mode is steadily increasing, as is the chance of needing an expensive ballast replacement.
LEDs have pretty much made this moot though, HID is dead for all practical purposes, all development and marketing has ceased and the quality of currently available lamps is dropping.