They're both unofficial Bond films and not included with the rest. All in all it makes perfect sense that these two are left out of the continuity. You have 25 official films on one hand (all made by EON). Then, in the other, you have one parody and one remake (neither made by EON). It's not rocket science.
One is a satire made by someone who bought the rights directly from Ian Fleming himself. Don't want it made - don't sell the rights. Same as Marvel selling off the rights to their characters and then struggling to bring their universe together once superhero films took off. In the end, they bought the rights from Fleming and could make it whatever they wanted, but also EON has the right to say it doesn't belong.
The other is a remake made by a producer (who, along with a scriptwriter) were left uncredited by Ian Fleming when he took an abandoned script they had all worked on and turned it into the novel Thunderball. The producer sued Fleming, battled in courts for many years, and eventually the producer won the ability to create "his" movie, which ultimately is a Thunderball remake because it was the same source material they had all collaborated on years earlier. It's Bond without many of the elements or actors from the Bond universe (from the EON films). Certain things had to be changed for legal reasons - no gun barrel sequence, no Bond theme music, different actors in prominent supporting roles, etc.
Another thing these two films are responsible for is the inability of EON to make a serious version of Casino Royale for many years or to reintroduce Spectre and Blofield - until they acquired the rights in legal battles and/or settlements with trustees and heirs.
