It is still based on a rumor, but with AMD APUs you all know there is an IGP installed, an integrated GPU if that makes it more understandable. Current, and near-future lines of APUs will still be based on VEGA (RDNA) micro architecure, and albeit NAVI has made a fashionable introduction for desktop, it seems that NAVI (RDNA2)will not reach AMD APUs before 2020.

As stated this is a rumor, one that comes from ExPreview. The Vega architecture would reach into Cézanne APUs that are expected to be released in 2021. And yeah, if you missed the news on it, Cézanne are APUs that will be based on ZEN3. In the article the Chinese website also makes mention of the fact that TSMC's 7nm process would still be used for this generation. And here's when we crank up the gossip up a notch, after Cézanne there's Rembrandt, these would be based on a TSMC's 6nm node and DDR5 DRAM memory. Here the APUs would switch towards the next, or second-generation RDNA architecture. It is also the timeframe where USB4 and PCI 4.0 would see its introduction into the range. 

AMD would also plan a low voltage processor series (Van Gogh) at giving or take 9 watts to take on Intel's Y-series. The Twitterer Komachi Ensaka has also posted an overview of what he expects from the next few years, you can see that listed below. These self-made plots however are based on stuff noticed and expected, and as such hold no validity as to what the final outcome is going to be, ergo I can only label them as rumors until further notice.

AMD APU Display Architecture to remain VEGA, phase out in 2022, mention of Rembrandt