Is there any chance that a model pack for minions will come?

At least for the Necromancer's minion ...

I'd buy it

it's not "minion" but "familiars".

Many topics already talks about it, and nobody knows, but many want.

If you have other similar games, try using figures from those other games. For example, I have the (older) Hero Quest game, which is quite well worn, many enjoyable sessions there, but that's a different topic. I use a Skeleton figure for the Reanimate. The Dwarf character works quite well for Splig. Other characters also work out for replacing the tokens. Their size is comparable to the Descent figures and it makes things a little more ... visually pleasing (for lack of other words).

Wouldn't that be problematic since many familiars are not counted as obstacles and can occupy the same space as other creatures?

Good point. Depends on the Familiar. But in this case, the Reanimate is treated as a figure that does block LOS and movement, but is considered a friendly figure for Hero movement.

At least Reanimate, Wolf, and Raven flocks are treated as figure and Stone as obstacles, so mini have some logic

Here is a previous thread on using proxies.