Can a dac really be future proof?

It was true then and it is now. You may prefer vinyl but digital is more exact at storage and playback. At any rate this thread is about DACs and digital. 

DACs will get better numbers

Do you listen to numbers?

On topic, there’s always the next best thing that’s so much better than the thing before. We’ve seen that a lot with different types of sound encoding and movies and TV displays. With audio though, how much more can the human ear actually hear beyond the high-res formats that are already available?

If it sounds good now, why wouldn't it sound good 10 years from now?

are any of us future proof?

only things that are future proof are 7-eleven straws and plastic drink bottles

Really future proof? As in SW only upgrades without a hardware upgrade? I don't see how future proof is possible in that light.   SW upgrades will keep obsolescence at bay but Hardware moves on every year.   So you spring big bucks for a 24 bit, 196 KHz DAC, there is no software upgrade going to covert that to a 32 bit, 384 KHz DAC.  

This. My experience includes DACs from both Schiit and Chord. I purchased the 1st gen Bifrost and had it upgraded twice (analog board and multibit). The next gen Bifrost2 was completely re-engineered making an upgrade from the 1st gen impossible. So much for future-proof. The Chord DAC started out as the Qute HD and was upgraded to EX when it became available, thinking I'd future-proofed a bit. 3 months later Chord released their brand spanking new version, the completely re-engineered Qutest. In particular, they overhauled the USB implementation (which they needed to do). In the meantime they stopped development of the HD/EX USB driver, which in a very short time rendered the USB connection to my Mac mini useless. Mind you, both DACs still work but the only upgrade path for either is to purchase new. BTW, the Chord experience was particularly painful. 

At least with the NAD M51 DAC they supported it as far as the architecture allowed, and thats fine by me.  They added features too, so you really can't ask for much more.  

One thing about the RME, its roots are in pro audio so the software side is much more solid than boutique DAC  brands.  Because all of their units are play/record , they use the same software and it has been debugged and refined.... it works perfectly.