What are the effects of abstaining from eating a certain flavor?

You nailed the correct wording in your question - "we become accustomed to". We tend to get used to and like what we become accustomed to.

For the same reason that we get used to overly salty things, we can get used to less salty things. What we get used to becomes normal and what we like.

I've experienced the salt reduction due to a health condition my husband has. We can no longer tolerate food with the same level of salt that we used to eat. By reducing the amount we use, we became accustomed to food with less salt.

I did the same thing with sugar in tea and coffee many years ago. I grew up with Southern style (very) sweet tea. I didn't gradually reduce it but cut it out all the way. To this day I don't use sugar in coffee or tea, add it to cereal (or buy frosted cereal) and I find many sweet things just too sweet for my taste.

I also liken this to learning to like new foods. There are many things I've tried and didn't like up front but, after continuing to try them, eventually found that I had learned to like these foods. One, for example is cilantro. When I first started tasting it I couldn't stand it. I swore that it tasted like soap. But after a while, I found myself really liking it. So much so, that I started adding it to many foods that ordinarily I wouldn't have thought to.

While taste is subjective, we can become accustomed to new things and often times need to.

I have personally experienced this with sweet as I reduced the amount of sugar (and sweeteners) I add to tea and coffee and I can at attest that I did get accustomed to less sweet to the point that when I had tea with the same amount of sugar as before it was far too sweet for me.

I didn't do a "big-bang" reduce by half all at once, I did it gradually over about a month until I was down to about half what I'd been adding. However, I found I hit a limit, if I reduced too much it was never sweet enough no matter how long I gave my taste to acclimate.

About 40 years ago I thought that 4 sugars in a coffee was perhaps a tad more than I really needed ;)

It took me maybe 4 years of gradual reduction - including about 6 months when I needed just that quarter spoon for the first cup then I would be OK without for the rest of the day.

Without actually intending to, by the time I'd got the sugar down to zero, I'd also stopped eating sweet things entirely. This was not any kind of 'health' or 'diet' thing, it just coincided with my gradual reduction of sugar in coffee.

To this day I cannot bear sugar in coffee. I rarely eat sweet things at all - it's not that I dislike them, I simply have little desire for them & when I do try, they're usually just far too sweet.

I've never tried it with salt... maybe it would work, but I have never felt the need to try. [I have some theories about salt addition, but they don't really belong here.]

It doesn't work with chilli. I've been a "chilli addict" since my teens & if I ever go a few weeks without anything seriously hot, it makes no difference; it's not suddenly 'hotter'. I'm not in any way 'chilli immune' but I do like it to bite back. [This applies not just to the pseudo-mexican dish, but to any type of 'curry' too.]