Answer No, its not true.

On the contrary a lot of investors had already pulled out their investments on the Philippines because of the recent tirades of Duterte. He even told investors to get out and instead he’ll deal with China and Russia which are willing to invest in the Philippines. The false news regarding Bill Gates plan to invest in the Philippines is from a sattirical news site named Guard1an.

Sources:

https://theguard1an.com/disclaimer/

https://theguard1an.com/duterte-attracts-more-investors-as-bill-gates-invests-20-billion-in-the-philippines/

http://www.gmanetwork.com/news/story/582398/news/nation/duterte-responds-lumayas-kayo-i-ll-deal-with-china-russia-instead#sthash.2wtYeJzw.dpuf