So Vegeta in chapter #40 powers up to another form. Is this form supposed to be super saiyan blue evolution? Is it supposed to be a different form?
no, it is a evolved form the the original SSB/SSJB (Super Saiyan Blue). This is noted, because of the darker blue around the edges of Vegeta's aura, and the regular SSB has no darker blue around the edges. This new SSB evolved form was never reached by Goku,at least in the anime series of Dragon Ball Super.
The evolved form of SSB has the FULL abilities of SSB, which the regular form only has for the first few seconds. Although SSB evolved is good, it is not as fast as SSG (Super Saiyan God).
So this is not the same form, it is an evolved form, and has the FULL potential of SSB, with no limitations whatsoever.
the following is a evolution chart for all of the Dragon Ball transformation (Saiyans only) (Includes all forms used by both Goku AND Vegeta)
Kaioken --> Super Vegeta --> SS1 --> SS first-grade --> SS second-grade --> SS2 --> SS3 --> SS4 --> SSG --> SSB --> SSR (Super Saiyan Rose, used by Goku Black) --> SSB Evolved (Vegeta was first to use this evolved form of SSB) --> UI --> MUI (UI exhausts the user, and MUI furthur exhausts the user, but when Goku used it, he would've died if he came out of it then)
I did my research on the Dragon Ball Wiki
It is not acknowledged as a new transformation and Super Saiyan Blue Evolution is a new transformation. Vegeta was in his mastered Super Saiyan Blue form and reached a higher state of the form in terms of raw power(Comparable to SSJB Goku powering up against Jiren in Episode 122). Another reason for stating the same is because the Super Saiyan Blue Evolution was considered to be an anime-exclusive form.
However, it is important to note that we won't know the exact answer for the question until Toyataro makes any comment with regard to the same.