Yes for some things, no for others. General board control, stance, balance, body movement for some tricks, etc: skateboarding definitely helps. There are some things that will feel unnatural at first though if you have skateboarded for a long time:

1) You want your weight biased towards your front foot on a snowboard, when you get competent at riding you will be doing a lot of control with the front foot. This is the opposite to skateboarding, where leaning on the front leg will cause you to fall over very quickly.

2) Toeside turns on a snowboard are utterly counterintuitive because there's no real mapping to anything on a skateboard (unlike heelside which could be considered like a fs powerslide on a skateboard) - you have to push your shins into your boots. Maybe it's a bit like carving on a longboard, but not so much.

The whole turning thing is the main difference - on a snowboard you use your front foot and your edges, on a skateboard you just pivot on the trucks.

(Source: 20 years as a skateboarder, now spend about 30 days a year on the slopes instead).

When I learnt I could already ski, was terrible at skateboarding, never got good enough to even ollie.

Did one day of 2x2 hour lesson, then could board well enough to do intermediate runs and manage on t-bar and chair lifts.

Most abiding memory, very cold arse. We broke for lunch after the first 2 hours and I had difficulty using the loo because I couldn't feel my arse at all.

Great fun, but for the last couple of days of the trip I went back to skis. There's something about the rhythmb that matched mountain-biking for me.

Day after the snowboarding lessons I couldn't sit up in bed, had to roll over, my tummy was so sore. I'd recommend lots of sit-ups and squats to get your abs ready!

I think it's easier to learn to board.

When I first tried snowboarding after skateboarding for many years, the hardest part to get used to was being strapped into the board. I instinctively wanted to adjust the position of my feet and run out of falls.

In my unscientific opinion, I think there is some skills overlap with skateboarding, surfing, and snowboarding. They all put your body at a 90 degree angle to the direction you're heading and you have to adjust your center of gravity over the board to turn. So it's very possible your skateboarding skills will help you learn faster than people who don't surf and skateboard.

If you can get a hold of a caster board (rip stick), I found the motion to translate perfectly [1]. My very first time snowboarding, within 10 feet down the slope I had flipped over myself hard probably 3 times. And when I managed to stand up for more than a few seconds, it felt like the board was just sliding and I had no control.

But then for some reason I thought to ride it like a rip stick. And it completely clicked. I made it all the way down that very first run from there. Some of my group members had snowboarded multiples times before that day, but I was pretty much instantly better than most of them. As a side note, I also used to skateboard and didn't feel like it helped at all.

[1] https://en.wikipedia.org/wiki/Caster_board

The way you lean to carve and drive with your feet and let your body follow is very much like long boarding IMO.

I never skated on a regular board but I'd say yes you will have it easier.

Only partially, because on snowboard you are bound to the board, so there is no jumping aside if things go bad, and the way to manage your balance is slightly different.

If you do it just like on the skateboard, you will fall a lot.

the basics of turning, carving, moguls, maintaining your speed etc wont necessarily feel analogous to skateboarding but the more advanced concepts especially when it comes to things like pipe & rails will feel pretty natural. the most fundamental difference imo is that skating pretty much all happens in your feet while you really have to throw your whole body to do anything on a snowboard.