"Pour le Mérite" models:
In 1994, Lange introduced the Tourbillon "Pour le Mérite," a limited edition featuring a fusée and chain as its distinguishing characteristic. Twelve years later, in 2006, Lange re-used the fusée and chain mechanism and "Pour le Mérite" concept when it launched the Tourbograph "Pour le Mérite" in a platinum LE of 51. I'd imagine some original Tourbillon "Pour le Mérite" owners might have been displeased at the re-use of what they previously thought was the sole distinguishing feature of their watch. Of course, one could argue that the Tourbograph was simply a delayed release that was part of Blumlein's pre-Richemont vision (vs. a later release done purely for expeditious financial reasons). One could also argue that original Tourbillon PLM owners might have actually felt better when the Tourbograph was released because the Tourbograph was even more complicated and costly than the original Tourbillon PLM. Neverthless, the Tourbograph did reintroduce a concept that some original Tourbillon PLM owners (not all, of course) might've previously considered "theirs" or not to be duplicated. But then, just 4 years later in 2010, Lange released the exact same watch (Tourbograph PLM) in its new, special, honey gold metal, in an LE of 50. That honey gold release seems more analogous to the present situation with the Richard Lange PLM.
In 2009, right before the honey gold Tourbograph was released, Lange introduced the Richard Lange "Pour le Mérite" (LE of 50 in PT and 200 in RG). Here Lange decided to offer a fusée and chain without even a Tourbillon. So in that regard, the Richard Lange PLM represented a considerably less complicated, less expensive, and less exclusive offering of the PLM concept and fusée and chain mechanism than the Tourbograph or the Tourbillion PLM, thereby arguably further diluting any special feeling that might have accompanied owning one of those earlier PLM models (Tourbograph or Tourbillon PLM). 
"Ursa Major" models:
In 1999, Lange released the Emil Lange 1815 Moonphase (LE of 150 PT, 250 RG). The only distinguishing aesthetic feature of this relatively simple watch was the display of Ursa Major (Big Dipper) on the dial. Just 4 years later (2003), and much to my personal surprise and disappointment (horror, actually), Lange reused that distinguishing feature on the dial of the Luna Mundi (LE of 101). At the time, I had a conversation with the then-president of Lange USA, who remarked that such behavior was uncharacteristic and surprising.
1815 models:
In 2009, Lange released the 233.025, which was a 40mm 1815 in a platinum case with rhodum dial. It was an "LE" of 500 originally priced at $33,000 USD. Because 500 were offered, it was available for sale over many years, and by 2015 its retail price was $39,000 USD. In 2015, Lange released the 236.025, which was identical in every way to the 233.025 except it had a black dial, fewer were made (LE of 200), AND the price was only $33,500 USD -- $5500 less than the 233.025 (an identical watch except for the dial color, black vs. rhodium)! Many buyers of the 236.025 thought they were buying "the" 200th Anniversary 1815. But as we know, shortly thereafter, Lange introduced the same watch yet again but in honey gold with eggshell dial (236.050) -- same $33,500 USD price and same LE of 200.
