To be fair, they did 'announce' most of these new DAPs earlier this year already. You'd have to follow these forums and their Facebook page to know that, but then many enthusiasts do. For example the M11 PRO will likely be followed by the M15 with dual AK4499 DACs, and will be the 'flagship' of the M-line.
If you break it down, their DAP roadmap is fairly simple: M6/M7/M9 make up the entry-level/midrange, all based on the same or similar SoC platform, and the M11/M11PRO/M15 make up the mid-to-high-end, all featuring the same Samsung SoC. So a total of six DAPs that cover all bases and cost points, which for a large Chinese company like FiiO isn't OTT.
By contrast A&K has FOUR different DAP tiers (A&ultima, A&futura, A&norma and KANN), each with their own variant models. Shanling has 6 different DAPs (at current count), and as does Cayin. I actually think FiiO have the most clearly laid-out lineup based on budget/need, and easily offer the best bang-for-buck based on what you're getting, exemplified by the M11 (which at $450 is my sweet spot price for a portable player). In fact until the M11 was released, $450 would buy you a very underwhelming DAP, certainly compared to the M11. Now you'd need to spend over double that to get anything similar in features and quality, which to me represents exceptional value.
The great thing about FiiO releasing their higher-end DAPs at previously midrange pricing is that other manufacturers have to follow suit, or at least work much harder to improve their higher-priced players.