I'm not so sure he is anti-piracy so much as he just values the money he spend on his past purchases and would rather retain their legitimacy. I can relate, even if the difference is only one of sentiment.
Not everyone is out to step on your toes, ya know.
If you are planning on doing a DSiware downgrade using the upcoming method, yes, you will be able to keep all your games, as the process will only require homebrew launcher access.
The new method will also require access to any one of the exploits that can get you into the homebrew launcher. At this time, unless you already have some secondary entry point installed, there is no public free primary entry points into the homebrew launcher on 10.7 and above.
I'd urge you to buy a copy of fieldrunners from the 3DS eShop in case it's removed when the new method becomes viable, keep in mind that there's no ETA on when the new method will become usable, so until then you're going to be a sitting duck.