The main implication of this news bit is the business. This only means MVP will be richer and that SMART is really making moves to become the biggest telecom service provider in the country, putting pressure on Globe.
We consumers don't have to worry about anything. Just because SUN is now under the same umbrella as SMART does not mean we will be losing the UNLI features.
PLDT said that it intends to keep the mobile operations of Digitel separate and intact, and to maintain and capitalize on Sun Cellular's operations and significant brand equity to continue serving specific segments of the market, especially those who prefer "unlimited" type of services.
Unless you are a Globe guy, there's really no reason for you to be alarmed by this news.
If you're concerned about there being a SMART monopoly, if you think about it SUN was never a real threat to either SMART or Globe. People usually have a Globe/SMART number and a separate SUN number, which only shows that they are only good for their UNLI services. Now that SMART has acquired SUN, they've given themselves a boost over Globe, and that's all there is to it.