Nah. I just caught her in 2017's HOSTILES and she would need a severe drop-off from then to appear older-looking than McGregor, whom I'd assume would play his younger self. It'll be one of those things like CGI Luke face when everyone's all, "Yeah, I'll go with this if the moment's right," which is going to happen because despite being a flashback it'll still strike forward progression in the story. It'll just be out of order, like the F&F franchise where their Han is older when he's younger and will come back to life multiple times. And it's fine.
The thing I worry about is finagling Rosario Dawson's movements. Inherited from the animated series, Ahsoka's movements aren't as easily sold in live-action. I hope they figure something out that doesn't taint that particular legacy.