Although i believe that Facebook Libra will be a success market after launching but still i don't believe that it will disrupt the current market as their platform is just the same with Bitcoin. Like you will use Libra coin to avail the FB services and to use the coin for investments then we have already Bitcoin which is the main source of that concept and the most trusted platform.
Facebook needs to prove itself as a better solution for micropayments than its competitors (like XRP) with the launch of Libra. To achieve this, it would need to provide better transaction capacity, and long-term stability unlike no other alternative cryptocurrency today. As Libra's aim is to be a stablecoin, it'll be used in the same way as the USD. Because of this, we cannot say that Libra will disrupt the financial/economic system. What it'll do is to give a boost to currently existent Fiat currencies (like in this case, the US Dollar).
Upon launch, Facebook could bring digital payments focusing mainly within unbanked people. That way, it could benefit the adoption of Blockchain technology, as unbanked people will get into other alternatives as well (like Bitcoin and other cryptocurrencies we know and love today). Despite the success Facebook might obtain with its Libra coin, it'll never be able to overcome Bitcoin in any way. Being extremely centralized is one of the main reasons why this won't happen anytime soon. With too many governments that are against Facebook's digital currency, it's becoming uncertain whenever it'll launch at all.
Nonetheless, Libra may not be able to disrupt our current economic system, but Blockchain technology will. Whenever it'll be via a government-issued cryptocurrency, or by another mainstream company with a focus of improving worldwide payments, it's yet to be seen. What's important is that Bitcoin's Blockchain technology has taken the world by storm, just as Satoshi predicted. Which is why, we'll be dealing with Blockchain tech without even noticing it within the not-so-distant future. Just my thoughts