Wikipedia lists five demands with an added rationale. I will quote them here, as those seem to be the the concerns of the protesters. Combined with the rationale, it seems neither of those have been addressed yet. From Wikipedia:
Permanent withdrawal of the extradition bill
While suspended on 15 June, the bill could be resurrected with its current "pending resumption of second reading" status, becoming law within a few days. Some pro-government political party members, like Ann Chiang, indicated that the bill could be resumed with additional promotion work after the protests cooled down.
Withdrawal of the "riot" characterization
The government had originally used the word "riot" to describe the 12 June protest. Later the description was amended to say there were some protesters who rioted. However protesters contest the existence of acts of rioting during the 12 June protest.
Unconditional release of all arrested protesters without charges
Protesters consider the arrests to be politically motivated; they question the legitimacy of policemen arresting protesters at hospitals using their confidential medical data in breach of patient privacy.
Independent investigation into police violence and abuse of power
Civic groups felt that the level of violence used by the police on 12 June, specifically those against protesters who were not committing any offences when they were set upon, was unjustified; Police performing stop-and-search to numerous passers-by near the protest site without probable cause was also considered abusive. Some officers' failure to display or show their police identification number or warrant card despite being required to do so by the Police General Orders is seen to be a breakdown of accountability. The existing watchdog lacks independence, and its functioning relies on police cooperation.
Carrie Lam to step down and implement full universal suffrage
The Chief Executive of Hong Kong and many other politicians lack legitimacy due to the absence of a democratic mandate.
With regard to your question, the first point seems the most relevant. Since the protesters are asking for the bill to be withdrawn permanently, something which hasn't happened yet, the protests still have the same basis as they did initially in that regard. The other demands follow from the protest and the government's response, but the first reflects the original aim of the protests.
In answer to your comment question:
The problem with the current version of "extradition" is that instead of being evaluated in a Hong Kong court, a representative of the Chinese government is simply allowed to approve extradition for crimes including things like protesting the Chinese government. If I may ask, what are you basing this on? Is there any offcial document that says so?
This is something that has been a concern, not just in the media but also from the European Union's point of view. Quoting from the European Parliament resolution of 18 July 2019 on the situation in Hong Kong (2019/2732(RSP)):
D. whereas the proposed bill could facilitate the rendition to China of people for political reasons and their exposure to a judicial system with serious human rights failings; whereas under the proposed amendments, the Hong Kong court would not have the clear, explicit jurisdiction and legal obligation to examine the various human rights involved in cases being handled by the courts in mainland China or in other countries;
The above resolution is dated July 2019. Earlier in May 2019, Reuters reported on the EU expressing concern stating:
Critics, including foreign governments, legal and business groups, have expressed fears the law could erode Hong Kong’s rule of law and leave individuals, including foreign nationals passing through the city, vulnerable to being sent back for an unfair trial on the mainland.
My question is: has anyone seen any evidence that the modified bill grants the central government the power to do things that concern the protesters?
Yes, section 1.4 of the bill deals with who may be surrendered:
A person in Hong Kong who is wanted in a prescribed place for prosecution, or for the imposition or enforcement of a sentence, in respect of a relevant offence against the law of that place may be arrested and surrendered to that place in accordance with the provisions of this Ordinance.
I did not find, nor does the above state, that the offense has to be an offense in Hong Kong. As such, without having seen anything in the bill to the contrary, the Chinese court system could ask for the extradition of an individual in Hong Kong on the basis of this proposed law.