"This is just a pure signal, a pure leadership sign that Verizon's going to be a leader in 5G," Armstrong, formerly CEO of AOL, told CNBC in an interview with "Mad Money" host Jim Cramer.
Verizon CTO Hans Vestberg will become CEO in August. Current CEO Lowell McAdam, who has run Verizon since 2011, will take on the role of executive chairman of the company's board.
"Verizon's been a leader in 1G to 4G," Armstrong said. "5G is really where the world's going and today's announcement, with Lowell stepping up to executive chairman and Hans coming in as CEO, really tells you how serious we are about 5G and building out the next layer of connected consumers."
Most major telecommunications companies are racing to establish 5G networks, which will represent the fifth generation of mobile internet connection and offer faster speeds and better connectivity for smartphones and the Internet of Things.
Armstrong argued that 5G will help Oath, the digital media giant that owns Yahoo and AOL, become "the largest media company ... connecting directly to mobile consumers."
Additionally, 5G will offer higher computing power that Oath hopes to leverage in its augmented reality and virtual reality ventures, the CEO said.
"For our business, [5G] represents a really quantum shift," Armstrong told Cramer on Friday. "If you like fantasy [sports] now, you're going to love VR, AR fantasy in real time, being able to follow not just the game, but individual players."
"5G is going to bring an enhancement that will feel like AR-VR-type-level content and services," the CEO continued. "That's why 5G is important. It's more speed, but it's also amazing amounts of compute power for us to do different types of content."
And while the $8 billion Oath doesn't have billions to spend on original content like entertainment juggernaut Netflix, Armstrong said that Verizon's sprawling mobile presence would help Oath get its original and branded content to consumers.
"What consumers want at the end of the day is they want to have a really good use of time, they want to know where they're getting their information from and they want to trust it," Armstrong said.
"There's 3 billion people connected right now. There's another 3 billion that are going to get connected. The vast majority of those are all going to be mobile connections, he continued. "If we can be the first company to bring trusted brands to that size audience overall, that represents an unbelievable opportunity for us as a business and that's what our global team is really excited about."