Absolutely. My colleague explained it very well a few minutes ago. When you ask people to fill out the form voluntarily, even if it seems to be completely normal and positive, it actually distorts the data in the census sampling process. In other words, the people who will answer are more likely to display specific characteristics. For example, they have more time or more education, so that they value the census or understand its importance better. So the data we get are not representative of the whole population, but rather of people who show goodwill or who like to take part in surveys.
So, at first glance, it is a small change that is well intentioned and can seem like a good idea. In fact, it is a technical change that will drastically alter the credibility and value of the census. At the end of the day, it is a rather technical debate, but it is still quite important given the repercussions on the quality of census data.