Final Fantasy (PSP) hard mode question

[Windowslm]

I just beat the anniversary edition of Final Fantasy I on the PSP and figured after I beat the 5 bonus dungeons I was done with the game, but then I learned about "hard mode" and playing through the game again for an added challenge as well as getting the last few art images.

I haven't found much info about hard mode, but my concern is the upgraded enemies. If I don't have 100% bestiary from the first play through, will any be gone from hard mode since it had replaced enemies with their upgraded versions?

Thanks in advance for any info you can provide on this.

tl;dr does hard mode contain every bestiary monster or are some removed b/c they have been upgraded?