No, it is not.
The trees are different than Night Elf trees. The color pallet in the zone is different. Structures are different. Literally the only similarity is that is is nature based. And Night Elves do NOT have a patent on that. Calling Ardenweald Night Elf is like calling Maldraxxus Forsaken just because it is undead stuff. Maldraxxus is actually closer to the Forsaken aesthetics than Ardenweald is Night Elf. And MAldraxxus is NOT Forsaken.
For reference, much of Ardenweald is inspired by Celtic mythology. Tir na nOg, the land of youth.
This kind of reasoning drives me nuts. You see it all the time. The rules seem to be:
*For a character to be Horde they have to be full on Lok Tar Ogar, For the Horde. They have to actively help the Horde specifically and never the Alliance.
*For a character to be Alliance they just have to have had any kind of friendly interaction with some Alliance character(s).
Ysara was part of a completely neutral organization. She never aided the Alliance against the Horde. She was never hostile to the Horde. She is not an Alliance character.
Sylvanas. 
More seriously there is a couple problems with that line of reasoning.
First, lets thinks about this. Who are the Forsaken mostly? Former citizens of Lordaeron. What this means is that most of the historically important characters to them were human members of the nation of Lordaeron. Players tend to call them Alliance. Example:
(Note: Not even true. Draka is the more prominent and important person in the zone)
Right there is an example. In truth, Alexandros Mograine actually has more connection to the Forsaken than the current Alliance. He was a member of the Silver hand, a Lordaeron group. He was a citizen of Lordaeron, killed and raised to undeath under the Lich king. Yes, he was part of the original Alliance. But so were the Forsaken.
So, the Forasaken lore connections are often just disregarded unless they happen in the very small window of basically WoW’s life.
And the second problem is simply put, Sylvanas. She has dominated Forsaken lore for way to long. They have been little more than her minions for a lot of time. So, yes there is a very real problem with their representation. But don’t try to pass it off as some slight where they were ignored. The Forsaken have gotten more attention than most races. The problem is to much of it has been completely centered around Sylvanas.
But not in WoW. This is some of your own perspective bleeding in. And that is understandable, and hard to avoid doing to some degree. Finding similarities and patterns is what humans do really well. But sometimes it leads to wrong conclusions. This is one of those times.
Nothing against that, I personally like Ysera and don’t mind helping her at all.