No matter how much glyphosate you use or don't use, you should ALWAYS keep your beds mulched at least ONCE a year.
Weed proof barriers are not always good at keeping mulched beds weed free 100%. It takes a little effort from your landscape contractor and you, as a homeowner as well.
Hand weeding is sometimes necessary. It's not always desired, but it's a MUST!!!
If you are having trouble keeping Bermuda grass out of your mulched beds, you should stay on top of it, every time you mow your lawn on a weekly basis, during the growing season.
Metal edging will help contain the mulch in place and away from the grass, but you have to keep an eye on the creepers that make their way into the beds. ALL warm season grasses creep whether we like it or not.