Sometimes yes, sometimes no. It all depends on how the producer made it. If there isn't much bus structure on the track, then you receive them closer to what the mixdown sounds like. If there is a lot of bus structure and plugin mixing, then it could sound different. With trackouts, our producers tend to leave most plugins off, and bounce is always from the track-level not the bus level (since that would not allow instrument separation). With many of the 'tonal' plugins being on the bus, you lose that on track-level exports.
You may say, well why can't they bounce down each track through the bus manually? Because much of the bus processing depends on the interaction of 2+ tracks. Without both tracks coming through that bus at one time, you can output a totally different sound. They even use automated panning techniques triggered by other tracks. Yes it gets deeper.
So, without getting even more technical, I would advise, if you are a confident mixer or have a solid engineer, you'll find the way you receive your trackouts is super convenient and clean with plenty of headroom and original high-quality to do as you wish with them.
If you prefer the sound of our mixing, you can still order the trackouts and just have our mix engineer mix it with your vocals, or just use our mixdown WAV file.