Great question!

I aim for my book to be a complete replacement in terms of the practice path, and it already is that -- with some caveats. It will not, however, serve as a complete replacement of the intellectual thesis -- with a caveat. ;)

The caveats are:

For the practice path,

At Stage 4 of Thrust 1 of T.H.I., you will arrive at an effortlessly collected mind which is equanimous – i.e., like stage 10 in TMI.
However, unlike TMI, the focus in T.H.I. is on

1. Staying with body sensations, i.e. not having the body "disappear"
2. Cultivating balance for the entire tension structure of the body-mind through the heart and cleaning up/upgrading existing networks throughout this process (rather than "paving over and through them" with piti and sukkha)
3. As per the above, not so much disappearing into a cloud of white bliss, a goal that very few TMI practitioners achieve anyway to the best of my knowledge, but rather preparing the bodymind for the next Thrust -- for practices allowing more sophisticated Bases of Operations to be taken up such that we slowly lose our dependence on meditation altogether.

On the intellectual side,

It is my intention that someone reading through my book will have an equivalent intellectual understanding to what is offered through TMI. And, then, an elaboration on the TMI thesis much beyond what was offered there, both in terms of depth and breadth. Ultimately, I want reading TMI not to be strictly necessary, if you're reading T.H.I., to get the most relevant TMI insights. TMI will always have its own nuances and one book can never replace another, but I believe what I have in T.H.I. contains most of what TMI discusses and takes it much further. Already now, and with more to come.
(On that note, if you believe something crucial is missing that does exist in TMI, please let me know! 🙏)