I think anyone drawing conclusions about what play styles will or won't be achievable through 5e based on what isn't available yet is jumping the gun by at least a year. Remember that we just got rules for character creation within the last couple weeks, and even those are still largely incomplete (races and classes missing, minimal number of backgrounds and feats, incomplete class progressions).
I don't understand how anyone can really think that they have enough information to draw conclusions about how 'modular' the final game is going to be.
I've pointing out myself in other threads, that it's not fair to judge the current 5e by what it is missing.
But "playstyles" is a tricky thing... it's not just something you can say "let's put this issue on hold, we'll come back and add support for playstyle XYZ next year". A playstyle is even quite hard to define (I hope however that they have already done that), but my concern is just that if you want to support a certain array of defined playstyles, you have to keep that in mind since day 1 of design, otherwise it's possible that the core rules takes a design direction that won't allow you later on.
I thought the example of "low-power" was quite simple, but there is a better example and that is low-complexity combat. In this case IMHO they took just the right path, starting with combat rules and action economy that are pretty simple. Tactical and narrative modules will build on that, and with this approach the game will support both low-complexity and high-complexity styles of running combat. Had they started with high-complexity, it would have been a mess later on, with the rules of combat already interconnected and balanced for high-complexity, to try and support a low-complexity version (try that starting from 3ed rules... it's not a job for the average DM).
Unless of course the OP is just right, and WotC intention is just to sprinkle "bits and pieces" of every edition so that anyone can say "oh look, this is like in my favourite edition, I'm sold". But they have to guess well which bits and pieces exactly define the feel of each edition.
The point of 5e is to be easy to houserule. The modules are just official houserules. That's not just me saying it, that's Mike Mearls's definition of modularity. Slow healing started off as a houserule for packet 1, and now it's an official module in packet 2.
There is quite a difference between a module i.e. official and playtested houserule which is presented and explained in the books, and a DIY houserule.
The reason why I (over)reacted in my previous post to the suggestion "remove races and add prebuilt racial classes" is that such thing is an example of something not really that simple to DIY, at least it requires time and experience. If I have to do that for 2-3 different areas of the game, I would probably be fine. More than that, and you start wondering why you pay for the books if the game you want to play needs that much DIY work.
