They will normally get indexed but it depends on the website they are on as to how long it takes and if it actually happens.

I find authority bookmarking sites get re-indexed very quickly. Often a matter hours.

No need to ping. Let them get crawled and/or indexed naturally.

Normally they get indexed in less than 1-2 hours (like digg, reddit, twitter, etc.)

Don't ping them unless you find they are not indexed (here you should check it manually!)