Greetings,
I know this is ambiguous but here it goes.
Probably yes.
Because that envelope contains most of the bacteria and yeast that tibicos probably contains. And it was freeze-dried.
The fermented drink will probably have the same taste as the tibicos made with "grains".
But
If the freeze dried mass was not from grains but from fermentation produced by already fermented kefir the ratio between different bacteria species and yeasts will be modified.
In the grains it is naturally conserved and this leads to different fermentation types and ratios which will probably not be respected by the fermentation with already made kefir.
So it is important if you are a purist, if it is freeze-dried kefir grains or freeze-dried bacterial mass resulted from using kefir drink as a starter.
Anyway, the freeze-dried kefir grains won't be able to reform grains again (at least from what i've read) and the symbiotic relationship and the species variety will break down after 2-3 fermentations leading to just 2 or 3 dominant species probably.
That is still healthy but not the same
Water kefirs and dairy kefirs contain very different bacteria that produces the matrix (the gel, be it dextran for water kefir, or kefiran for milk kefir, totally different) which holds all the other species together.
I've heard of cases where you can use water kefir to ferment milk (and it works because the lactic bateria will coagulate milk) and milk kefir to ferment sweet water, but the end products will differ in qualities of taste and organic compounds and the kefirs will slowly die because of the unsuitable medium. You have to see them as a complex relationship between different bacteria and yeasts which nourish one another. Eliminate one and you will loose the whole factory.
Long story short water kefir should ferment sweet water and it will slowly starve in milk.