Generally speaking, becoming a bhikkhu enables a person to go on full time meditation retreat to meditate, study the dhamma, and follow the practicing guidelines. If just a few years after ordination a bhikkhu engages in various projects that makes him just as busy with worldly activities as in the lay life then that can greatly compromise his meditation development. This is not very different from the lay life . Personally, I would discourage this way of practice.
When it comes to monks who only begin taking up various projects after 20 years of practice, then I think it is a good idea. We need experienced / developed monks to get involved and offer their guidance, or motivating the population at large to do their part in improving the society they live in ( although not perfecting it). The Buddha didn't just encourage lay people to refrain from negative actions, but he also emphasized engaging in wholesome activities. I think this aspect needs to be highlighted as well.
Are we negating meditation development or embodying the dhamma by doing this ? I would say no because the inner development is still a priority in Theravada because the first 10 or 20 years should be fully dedicated to meditation development/ dhamma study/ following the practicing guidelines. This way if they decided to start teaching afterward, the quality of the teaching that we are getting can higher . If they decided to take up social activities also, it can be more effective when compassion is also guided by wisdom. However, I don't think it is a good idea at all for newly ordained monks ( after a few years) to begin taking up various activities from then onward. I doubt that it is conducive to their meditation development. Bhikkhu Bodhi is not one of them so I would support his dhamma & compassionate work.
Let's Ajahn Chah was fully developed and done what has to be done in the holy life and after 15 years of practice he came out of the forest to guide others in various projects to improve society at large, would it be necessary to tell him that he should go back and practice when he already finished with that task. I would say no.
Let's say after 15 years of practice a monk haven't directly experienced the teaching , but he decided that he wanted to start focusing on contributing to society through some compassionate work, should we tell him to go back and focus on the practice? I think at least he had done his best and dedicated a considerable amount of time to his practice ( correctly or not) , how much more time can we expect him spend on practicing.
I think both sides have a point, when we put it together we can see a fuller picture. Neither practice can be left out ,nor can we leave out dhamma teaching and compassionate work. The Buddha himself spends 6 years ( it might take longer for others) developing himself before even starting on dhamma teaching for the benefit of other beings. It is a good idea for monastics to follow that model and dedicate time to focus on inner development first before starting on improving the outer world.