Most of the cell towers and infrastructure has been built in 2 years - it's been incredibly fast. Once the telco licenses were awarded, the two telcos (Ooredoo and Telenor) didn't waste any time revving up ops.
Together with Android devices falling rapidly in price, it has been a complete transformation in connectivity.
There are some really positive outcomes, like a group of CS students in Yangon being able to follow Harvard CS MOOC's, and a lot of people working as devs being able to learn from stackoverflow etc. Internet connectivity will empower people to educate themselves but it will take some time.
In terms of commercial opportunities for tech companies, I'm not sure they exist in the scale the article depicts. There are between 50 and 60 million people, but most of the population live in the countryside, with very little spending power. The total market size for internet connected people with some (not very much) spending power is probably around 10 million.
The main challenges are with governance, and physical infrastructure, which are decades behind where they need to be for a functional country, and these are things internet connectivity unfortunately can't fix.