100% not going to happen, I have a good friend whose Dad is a retired PLA medic and she assures me no chance. They don't need the cost, the hassle and reunification will come with time and a subsequent desire for a better standard of living.
Gonna come back to this again as I'm in Taiwan now.
The idea that "desire for a better standard of living" will cause Taiwan to join China is deeply flawed. First, GDP per capita in Taiwan is 35,000 USD, whereas in China it is 12,000 USD, so it isn't clear how joining China would lead to a better standard of living.
Secondly, even if it would, that wouldn't mean Taiwan would return. Your friend is thinking in the quite typical (and flawed) Chinese mentality that money and economic development determines everything. UK was richer than Ireland for most of its independence but that didn't mean Ireland wanted to join UK, there are many such examples... for example, Japanese Manchuria and Japanese Taiwan were more economically advanced than independent China, but that doesn't mean that the rest of China wanted to be ruled by Japan.
There are also many benefits to living in Taiwan over China that are wholly unrelated to economics - chiefly unrestricted access to open Internet but also a more tolerant and pluralist society overall, and greater respect for sexual and ethnic/cultural minorities etc.
Also, another reason it won't come with time is the differing paths China and Taiwan are taking. Taiwan has taken steps to promote and protect minority languages and cultures while China is taking an aggressive approach to Sinicisation. Taiwan encourages immigration to counter low birth rates while China is increasingly xenophobic and barriers and conditions for foreigners have gotten worse over the last decade rather than better; despite the much smaller population Taiwan has a foreign population likely larger than all of China excluding Hong Kong, predominantly from Indonesia, Philippines, Vietnam, and Thailand. These account for 3.5% of Taiwan's population and over the next couple decades will likely increase significantly, causing further cultural divergence from China.
Also, the DPP are pursuing an economic strategy of promoting economic ties with India and SE Asia to reduce dependency on trade with China. As India and SE Asia develop relative to China, China's economic influence over Taiwan will decline as cultures diverge.
Also, China's intranet means it is diverging culturally from the rest of the world, which is converging due to a shared online space. This lies at the root of diverging cultural attitudes and worldviews between Taiwan and China.
And lastly, it is almost 120 years since Taiwan was unified with China, and 75 years since the arrival of large numbers of Guomindang from the mainland. Divergence in identity is only natural as time from these two events grows longer.
So you can see that time is definitely not on the side of reunification.