I have two Yorkies that are basically the same age. One is doing great going outside and the other was wee wee pad trained. The one that was wee wee pad trained hates to go outside so I've kept the wee wee pads and try walking her. I personally wouldn't let a dog go inside because it confuses them but I feel like I have to now. If you don't mind having a dog eliminating in your house and buying wee wee pads forever go for it! I would stay away from it especially if your little one is doing good going outside but the choice is yours of course
Good luck with your training!