IMO if Indonesia wishes to tax expats it is more likely to tax those non-resident foreigners who have nominee or Hak Pakai title on villas in Bali and rent them out, with or without a Pondok Wisata, and not declaring the income. That doesn't mean the Tax office would get much revenue but Hotel and Resort Owners are pushing to have those rental units out of competition.
Some officials recently came around where I live to check on IMB's and resident's status.
All expats with work-permits in Indonesia have to comply with declaring tax on income as do foreign owned Companies operating in RI. In 2016 this has been recorded at only 44,000 expat IMTA's issued....
How Many Expats Live in Indonesia?
The amount of RI tax 'possibly' recoverable from resident retired, or non-working, expats from their 'overseas' pensions or investments is less than a drop in the bucket.
IMO it doesn't seem worth the effort to crack down in this area, for no real result, as it would also be counter-productive to the stated President's aim to increase Foreign Investment and currency exchange.